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<div><span class="kw">theorem </span><span class="lab"><font color="Green" title="E21">Th23</font></span>: <a NAME="T23"><span class="comment"><font color="firebrick">:: PDIFF_9:23</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">m</font>, <font color="Olive" title="b2">n</font> being   non  <a href="ordinal1.html#V8" title="ORDINAL1:attr.8">zero</a>   <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of  <a href="numbers.html#NK1" title="NUMBERS:NK.1">NAT</a> <br/>  for <font color="Olive" title="b3">f</font> being   <a href="partfun1.html#NM1" title="PARTFUN1:NM.1">PartFunc</a> of <span class="p1">(<span class="default"><a href="euclid.html#K1" title="EUCLID:func.1">REAL</a> <font color="Olive" title="b1">m</font></span>)</span>,<span class="p1">(<span class="default"><a href="euclid.html#K1" title="EUCLID:func.1">REAL</a> <font color="Olive" title="b2">n</font></span>)</span><br/>  for <font color="Olive" title="b4">g</font> being   <a href="struct_0.html#NM12" title="STRUCT_0:NM.12">PartFunc</a> of <span class="p1">(<span class="default"><a href="real_ns1.html#K4" title="REAL_NS1:func.4">REAL-NS</a> <font color="Olive" title="b1">m</font></span>)</span>,<span class="p1">(<span class="default"><a href="real_ns1.html#K4" title="REAL_NS1:func.4">REAL-NS</a> <font color="Olive" title="b2">n</font></span>)</span><br/>  for <font color="Olive" title="b5">X</font> being   <a href="subset_1.html#NM2" title="SUBSET_1:NM.2">Subset</a> of <span class="p1">(<span class="default"><a href="euclid.html#K1" title="EUCLID:func.1">REAL</a> <font color="Olive" title="b1">m</font></span>)</span><br/>  for <font color="Olive" title="b6">Y</font> being   <a href="struct_0.html#NM2" title="STRUCT_0:NM.2">Subset</a> of <span class="p1">(<span class="default"><a href="real_ns1.html#K4" title="REAL_NS1:func.4">REAL-NS</a> <font color="Olive" title="b1">m</font></span>)</span><br/>  for <font color="Olive" title="b7">i</font> being   <a href="ordinal1.html#NM6" title="ORDINAL1:NM.6">Nat</a>  st 1 <a href="xxreal_0.html#R1" title="XXREAL_0:pred.1">&lt;=</a> <font color="Olive" title="b7">i</font> &amp; <font color="Olive" title="b7">i</font> <a href="xxreal_0.html#R1" title="XXREAL_0:pred.1">&lt;=</a> <font color="Olive" title="b1">m</font> &amp; <font color="Olive" title="b5">X</font> is  <a href="pdiff_7.html#V1" title="PDIFF_7:attr.1">open</a>  &amp; <font color="Olive" title="b4">g</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b3">f</font> &amp; <font color="Olive" title="b5">X</font> <a href="hidden.html#R1" title="HIDDEN:pred.1">=</a> <font color="Olive" title="b6">Y</font> holds <br/>( <font color="Olive" title="b3">f</font> <a href="pdiff_7.html#R2" title="PDIFF_7:pred.2">is_partial_differentiable_on</a> <font color="Olive" title="b5">X</font>,<font color="Olive" title="b7">i</font> &amp; <font color="Olive" title="b3">f</font> <a href="pdiff_7.html#K2" title="PDIFF_7:func.2">`partial|</a> (<font color="Olive" title="b5">X</font>,<font color="Olive" title="b7">i</font>) <a href="pdiff_7.html#R4" title="PDIFF_7:pred.4">is_continuous_on</a> <font color="Olive" title="b5">X</font> iff ( <font color="Olive" title="b4">g</font> <a href="pdiff_1.html#R7" title="PDIFF_1:pred.7">is_partial_differentiable_on</a> <font color="Olive" title="b6">Y</font>,<font color="Olive" title="b7">i</font> &amp; <font color="Olive" title="b4">g</font> <a href="pdiff_1.html#K14" title="PDIFF_1:func.14">`partial|</a> (<font color="Olive" title="b6">Y</font>,<font color="Olive" title="b7">i</font>) <a href="nfcont_1.html#R3" title="NFCONT_1:pred.3">is_continuous_on</a> <font color="Olive" title="b6">Y</font> ) )</div></div>
