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<div><span class="kw">theorem </span><a NAME="T4"><span class="comment"><font color="firebrick">:: TEX_2:4</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">S</font> being   non  <a href="zfmisc_1.html#V1" title="ZFMISC_1:attr.1">trivial</a>   <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a> <br/>  for <font color="Olive" title="b2">y</font> being    <a href="subset_1.html#M1" title="SUBSET_1:mode.1">Element</a> of <font color="Olive" title="b1">S</font> holds  <span class="p1"><a href="domain_1.html#K6" title="DOMAIN_1:func.6">{</a><span class="default"><font color="Olive" title="b2">y</font></span><a href="domain_1.html#K6" title="DOMAIN_1:func.6">}</a></span> is  <a href="subset_1.html#V1" title="SUBSET_1:attr.1">proper</a>  ;<br/></div></div>
