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<div><span class="kw">theorem </span><a NAME="T3"><span class="comment"><font color="firebrick">:: PRALG_1:3</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">A</font>, <font color="Olive" title="b2">B</font> being   non  <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a>   <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a>  holds   <a href="pralg_1.html#K6" title="PRALG_1:func.6">Inv</a> (<font color="Olive" title="b1">A</font>,<font color="Olive" title="b2">B</font>) is  <a href="funct_1.html#V2" title="FUNCT_1:attr.2">one-to-one</a> </div></div>
