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<div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="23_1_1_1"><span class="kw">per </span></a><a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="kw">cases </span></a><span class="hide"><a NAME="E1:23_1_1_1"/>
( ( <font color="Maroon" title="c4">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c6">i2</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">j2</font> ) or ( <font color="Maroon" title="c4">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c6">i2</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">j2</font> ) or ( <font color="Maroon" title="c4">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c6">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">j2</font> ) or ( <font color="Maroon" title="c4">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c6">i2</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 ) )
 </span><span class="kw">by</span> <span class="lab"><a class="txt" href="#E5:23"><span class="lab"><font color="Green" title="E17">A3</font></span></a></span>;<br/><div class="add"><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="23_1_1_1_1"><span class="kw">suppose </span></a><a NAME="E1:23_1_1_1_1"/><span class="lab"><font color="Green" title="E18">A4</font></span>: 
( <font color="Maroon" title="c4">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c6">i2</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">j2</font> )
 ; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide">  ex <font color="Olive">b<sub>1</sub></font> being   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <span class="p1">(<span class="default"><a href="euclid.html#K15" title="EUCLID:func.15">TOP-REAL</a> 2</span>)</span> st <br/> for <font color="Olive" title="b2">i1</font>, <font color="Olive" title="b3">j1</font>, <font color="Olive" title="b4">i2</font>, <font color="Olive" title="b5">j2</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>  st <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b2">i1</font>,<span class="p1">(<span class="default"><font color="Olive" title="b3">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font>) ) holds <br/>( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Olive" title="b2">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Olive" title="b5">j2</font>) )</span><br/><div class="add"><span class="kw">take </span>
 <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>)
; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide">  for <font color="Olive" title="b1">i1</font>, <font color="Olive" title="b2">j1</font>, <font color="Olive" title="b3">i2</font>, <font color="Olive" title="b4">j2</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>  st <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b1">i1</font>,<span class="p1">(<span class="default"><font color="Olive" title="b2">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font>) ) holds <br/>( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Olive" title="b1">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Olive" title="b4">j2</font>) )</span><br/><span class="kw">let </span><font color="Maroon" title="c8">i19</font>, <font color="Maroon" title="c9">j19</font>, <font color="Maroon" title="c10">i29</font>, <font color="Maroon" title="c11">j29</font> be   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> ( <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) implies ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )</span><br/><span class="kw">assume </span><span class="kw">that </span><br/><a NAME="E2:23_1_1_1_1"/><span class="lab"><font color="Green" title="E19">A5</font></span>: 
<span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font>
 <span class="kw">and </span><br/><a NAME="E3:23_1_1_1_1"/><span class="lab"><font color="Green" title="E20">A6</font></span>: 
<span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font>
 <span class="kw">and </span><br/><a NAME="E4:23_1_1_1_1"/><span class="lab"><font color="Green" title="E21">A7</font></span>: 
<font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>)
 <span class="kw">and </span><br/><a NAME="E5:23_1_1_1_1"/><span class="lab"><font color="Green" title="E22">A8</font></span>: 
<font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>)
 ; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> ( ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )</span><br/><a NAME="E6:23_1_1_1_1"/>
( <font color="Maroon" title="c4">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c8">i19</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c9">j19</font> )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E3:23"><span class="lab"><font color="Green" title="E15">A1</font></span></a>, <a class="txt" href="#E2:23_1_1_1_1"><span class="lab"><font color="Green" title="E19">A5</font></span></a>, <a class="txt" href="#E4:23_1_1_1_1"><span class="lab"><font color="Green" title="E21">A7</font></span></a>, <a class="ref" href="goboard1.html#T5" onmouseover="rs('goboard1/T5')" onmouseout="rh()">GOBOARD1:5</a></span>;<br/><span class="kw">hence </span><a NAME="E7:23_1_1_1_1"/>
( ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<font color="Maroon" title="c5">j1</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E4:23"><span class="lab"><font color="Green" title="E16">A2</font></span></a>, <a class="txt" href="#E1:23_1_1_1_1"><span class="lab"><font color="Green" title="E18">A4</font></span></a>, <a class="txt" href="#E3:23_1_1_1_1"><span class="lab"><font color="Green" title="E20">A6</font></span></a>, <a class="txt" href="#E5:23_1_1_1_1"><span class="lab"><font color="Green" title="E22">A8</font></span></a>, <a class="ref" href="goboard1.html#T5" onmouseover="rs('goboard1/T5')" onmouseout="rh()">GOBOARD1:5</a></span>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> verum</span><br/></div><span class="kw">end;</span></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="23_1_1_1_2"><span class="kw">suppose </span></a><a NAME="E1:23_1_1_1_2"/><span class="lab"><font color="Green" title="E18">A9</font></span>: 
( <font color="Maroon" title="c4">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c6">i2</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">j2</font> )
 ; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide">  ex <font color="Olive">b<sub>1</sub></font> being   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <span class="p1">(<span class="default"><a href="euclid.html#K15" title="EUCLID:func.15">TOP-REAL</a> 2</span>)</span> st <br/> for <font color="Olive" title="b2">i1</font>, <font color="Olive" title="b3">j1</font>, <font color="Olive" title="b4">i2</font>, <font color="Olive" title="b5">j2</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>  st <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b2">i1</font>,<span class="p1">(<span class="default"><font color="Olive" title="b3">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font>) ) holds <br/>( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Olive" title="b2">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Olive" title="b5">j2</font>) )</span><br/><div class="add"><span class="kw">take </span>
 <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>)
; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide">  for <font color="Olive" title="b1">i1</font>, <font color="Olive" title="b2">j1</font>, <font color="Olive" title="b3">i2</font>, <font color="Olive" title="b4">j2</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>  st <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b1">i1</font>,<span class="p1">(<span class="default"><font color="Olive" title="b2">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font>) ) holds <br/>( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Olive" title="b1">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Olive" title="b4">j2</font>) )</span><br/><span class="kw">let </span><font color="Maroon" title="c8">i19</font>, <font color="Maroon" title="c9">j19</font>, <font color="Maroon" title="c10">i29</font>, <font color="Maroon" title="c11">j29</font> be   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> ( <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) implies ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )</span><br/><span class="kw">assume </span><span class="kw">that </span><br/><a NAME="E2:23_1_1_1_2"/><span class="lab"><font color="Green" title="E19">A10</font></span>: 
<span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font>
 <span class="kw">and </span><br/><a NAME="E3:23_1_1_1_2"/><span class="lab"><font color="Green" title="E20">A11</font></span>: 
<span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font>
 <span class="kw">and </span><br/><a NAME="E4:23_1_1_1_2"/><span class="lab"><font color="Green" title="E21">A12</font></span>: 
<font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>)
 <span class="kw">and </span><br/><a NAME="E5:23_1_1_1_2"/><span class="lab"><font color="Green" title="E22">A13</font></span>: 
<font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>)
 ; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> ( ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )</span><br/><a NAME="E6:23_1_1_1_2"/>
( <font color="Maroon" title="c4">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c8">i19</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c9">j19</font> )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E3:23"><span class="lab"><font color="Green" title="E15">A1</font></span></a>, <a class="txt" href="#E2:23_1_1_1_2"><span class="lab"><font color="Green" title="E19">A10</font></span></a>, <a class="txt" href="#E4:23_1_1_1_2"><span class="lab"><font color="Green" title="E21">A12</font></span></a>, <a class="ref" href="goboard1.html#T5" onmouseover="rs('goboard1/T5')" onmouseout="rh()">GOBOARD1:5</a></span>;<br/><span class="kw">hence </span><a NAME="E7:23_1_1_1_2"/>
( ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c4">i1</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c5">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E4:23"><span class="lab"><font color="Green" title="E16">A2</font></span></a>, <a class="txt" href="#E1:23_1_1_1_2"><span class="lab"><font color="Green" title="E18">A9</font></span></a>, <a class="txt" href="#E3:23_1_1_1_2"><span class="lab"><font color="Green" title="E20">A11</font></span></a>, <a class="txt" href="#E5:23_1_1_1_2"><span class="lab"><font color="Green" title="E22">A13</font></span></a>, <a class="ref" href="goboard1.html#T5" onmouseover="rs('goboard1/T5')" onmouseout="rh()">GOBOARD1:5</a></span>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> verum</span><br/></div><span class="kw">end;</span></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="23_1_1_1_3"><span class="kw">suppose </span></a><a NAME="E1:23_1_1_1_3"/><span class="lab"><font color="Green" title="E18">A14</font></span>: 
( <font color="Maroon" title="c4">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c6">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">j2</font> )
 ; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide">  ex <font color="Olive">b<sub>1</sub></font> being   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <span class="p1">(<span class="default"><a href="euclid.html#K15" title="EUCLID:func.15">TOP-REAL</a> 2</span>)</span> st <br/> for <font color="Olive" title="b2">i1</font>, <font color="Olive" title="b3">j1</font>, <font color="Olive" title="b4">i2</font>, <font color="Olive" title="b5">j2</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>  st <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b2">i1</font>,<span class="p1">(<span class="default"><font color="Olive" title="b3">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font>) ) holds <br/>( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Olive" title="b2">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Olive" title="b5">j2</font>) )</span><br/><div class="add"><span class="kw">take </span>
 <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>)
; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide">  for <font color="Olive" title="b1">i1</font>, <font color="Olive" title="b2">j1</font>, <font color="Olive" title="b3">i2</font>, <font color="Olive" title="b4">j2</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>  st <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b1">i1</font>,<span class="p1">(<span class="default"><font color="Olive" title="b2">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font>) ) holds <br/>( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Olive" title="b1">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Olive" title="b4">j2</font>) )</span><br/><span class="kw">let </span><font color="Maroon" title="c8">i19</font>, <font color="Maroon" title="c9">j19</font>, <font color="Maroon" title="c10">i29</font>, <font color="Maroon" title="c11">j29</font> be   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> ( <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) implies ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )</span><br/><span class="kw">assume </span><a NAME="E2:23_1_1_1_3"/><span class="lab"><font color="Green" title="E19">A15</font></span>: 
( <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) )
 ; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> ( ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )</span><br/><a NAME="E3:23_1_1_1_3"/><span class="kw">then </span>
( <font color="Maroon" title="c6">i2</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c9">j19</font> )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E3:23"><span class="lab"><font color="Green" title="E15">A1</font></span></a>, <a class="txt" href="#E4:23"><span class="lab"><font color="Green" title="E16">A2</font></span></a>, <a class="ref" href="goboard1.html#T5" onmouseover="rs('goboard1/T5')" onmouseout="rh()">GOBOARD1:5</a></span>;<br/><span class="kw">hence </span><a NAME="E4:23_1_1_1_3"/>
( ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c6">i2</font>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E3:23"><span class="lab"><font color="Green" title="E15">A1</font></span></a>, <a class="txt" href="#E4:23"><span class="lab"><font color="Green" title="E16">A2</font></span></a>, <a class="txt" href="#E1:23_1_1_1_3"><span class="lab"><font color="Green" title="E18">A14</font></span></a>, <a class="txt" href="#E2:23_1_1_1_3"><span class="lab"><font color="Green" title="E19">A15</font></span></a>, <a class="ref" href="goboard1.html#T5" onmouseover="rs('goboard1/T5')" onmouseout="rh()">GOBOARD1:5</a></span>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> verum</span><br/></div><span class="kw">end;</span></div><div><a class="txt" onclick="hsNdiv(this)" href="javascript:()" title="23_1_1_1_4"><span class="kw">suppose </span></a><a NAME="E1:23_1_1_1_4"/><span class="lab"><font color="Green" title="E18">A16</font></span>: 
( <font color="Maroon" title="c4">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c6">i2</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c7">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 )
 ; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide">  ex <font color="Olive">b<sub>1</sub></font> being   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <span class="p1">(<span class="default"><a href="euclid.html#K15" title="EUCLID:func.15">TOP-REAL</a> 2</span>)</span> st <br/> for <font color="Olive" title="b2">i1</font>, <font color="Olive" title="b3">j1</font>, <font color="Olive" title="b4">i2</font>, <font color="Olive" title="b5">j2</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>  st <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b2">i1</font>,<font color="Olive" title="b3">j1</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b2">i1</font>,<span class="p1">(<span class="default"><font color="Olive" title="b3">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b4">i2</font>,<font color="Olive" title="b5">j2</font>) ) holds <br/>( <font color="Olive" title="b2">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">i2</font> &amp; <font color="Olive" title="b3">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b5">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive">b<sub>1</sub></font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Olive" title="b2">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Olive" title="b5">j2</font>) )</span><br/><div class="add"><span class="kw">take </span>
 <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>)
; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide">  for <font color="Olive" title="b1">i1</font>, <font color="Olive" title="b2">j1</font>, <font color="Olive" title="b3">i2</font>, <font color="Olive" title="b4">j2</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>  st <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b1">i1</font>,<font color="Olive" title="b2">j1</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b1">i1</font>,<span class="p1">(<span class="default"><font color="Olive" title="b2">j1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Olive" title="b3">i2</font>,<font color="Olive" title="b4">j2</font>) ) holds <br/>( <font color="Olive" title="b1">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">i2</font> &amp; <font color="Olive" title="b2">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b4">j2</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Olive" title="b1">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Olive" title="b4">j2</font>) )</span><br/><span class="kw">let </span><font color="Maroon" title="c8">i19</font>, <font color="Maroon" title="c9">j19</font>, <font color="Maroon" title="c10">i29</font>, <font color="Maroon" title="c11">j29</font> be   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> ( <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font> &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) &amp; <font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) &amp;  not <!--HUMANRECFAILED-->( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) implies ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )</span><br/><span class="kw">assume </span><span class="kw">that </span><br/><a NAME="E2:23_1_1_1_4"/><span class="lab"><font color="Green" title="E19">A17</font></span>: 
<span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font>
 <span class="kw">and </span><br/><a NAME="E3:23_1_1_1_4"/><span class="lab"><font color="Green" title="E20">A18</font></span>: 
<span class="p1"><a href="tarski.html#K4" title="TARSKI:func.4">[</a><span class="default"><font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font></span><a href="tarski.html#K4" title="TARSKI:func.4">]</a></span> <a href="hidden.html#R2" title="HIDDEN:pred.2">in</a>  <a href="matrix_0.html#K2" title="MATRIX_0:func.2">Indices</a> <font color="Maroon" title="c2">G</font>
 <span class="kw">and </span><br/><a NAME="E4:23_1_1_1_4"/><span class="lab"><font color="Green" title="E21">A19</font></span>: 
<font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <font color="Maroon" title="c3">k</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>)
 <span class="kw">and </span><br/><a NAME="E5:23_1_1_1_4"/><span class="lab"><font color="Green" title="E22">A20</font></span>: 
<font color="Maroon" title="c1">f</font> <a href="partfun1.html#K7" title="PARTFUN1:func.7">/.</a> <span class="p1">(<span class="default"><font color="Maroon" title="c3">k</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1</span>)</span> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c2">G</font> <a href="matrix_0.html#K3" title="MATRIX_0:func.3">*</a> (<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>)
 ; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> ( ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )</span><br/><a NAME="E6:23_1_1_1_4"/>
( <font color="Maroon" title="c4">i1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c8">i19</font> &amp; <font color="Maroon" title="c5">j1</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c9">j19</font> )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E3:23"><span class="lab"><font color="Green" title="E15">A1</font></span></a>, <a class="txt" href="#E2:23_1_1_1_4"><span class="lab"><font color="Green" title="E19">A17</font></span></a>, <a class="txt" href="#E4:23_1_1_1_4"><span class="lab"><font color="Green" title="E21">A19</font></span></a>, <a class="ref" href="goboard1.html#T5" onmouseover="rs('goboard1/T5')" onmouseout="rh()">GOBOARD1:5</a></span>;<br/><span class="kw">hence </span><a NAME="E7:23_1_1_1_4"/>
( ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<font color="Maroon" title="c9">j19</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c8">i19</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c9">j19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<font color="Maroon" title="c10">i29</font>,<font color="Maroon" title="c11">j29</font>) ) or ( <font color="Maroon" title="c8">i19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c10">i29</font> &amp; <font color="Maroon" title="c9">j19</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Maroon" title="c11">j29</font> <a href="nat_1.html#K1" title="NAT_1:func.1">+</a> 1 &amp;  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c4">i1</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c7">j2</font>) <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a>  <a href="goboard5.html#K3" title="GOBOARD5:func.3">cell</a> (<font color="Maroon" title="c2">G</font>,<span class="p1">(<span class="default"><font color="Maroon" title="c8">i19</font> <a href="nat_d.html#K7" title="NAT_D:func.7">-'</a> 1</span>)</span>,<font color="Maroon" title="c11">j29</font>) ) )
 <span class="kw">by</span> <span class="lab"><a class="txt" href="#E4:23"><span class="lab"><font color="Green" title="E16">A2</font></span></a>, <a class="txt" href="#E1:23_1_1_1_4"><span class="lab"><font color="Green" title="E18">A16</font></span></a>, <a class="txt" href="#E3:23_1_1_1_4"><span class="lab"><font color="Green" title="E20">A18</font></span></a>, <a class="txt" href="#E5:23_1_1_1_4"><span class="lab"><font color="Green" title="E22">A20</font></span></a>, <a class="ref" href="goboard1.html#T5" onmouseover="rs('goboard1/T5')" onmouseout="rh()">GOBOARD1:5</a></span>; <a class="txt" onmouseover="tooltip.show('hs',this)" onmouseout="tooltip.hide()" onclick="hs(this)" href="javascript:()"><span class="comment"><font color="firebrick">::  thesis: </font></span></a><span class="hide"> verum</span><br/></div><span class="kw">end;</span></div></div><span class="kw">end;</span></div>

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