<?xml version="1.0"?>
<div><span class="kw">theorem </span><a NAME="T89"><span class="comment"><font color="firebrick">:: GROUP_23:89</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">G</font> being   <a href="group_1.html#NM1" title="GROUP_1:NM.1">Group</a><br/>  for <font color="Olive" title="b2">I</font> being   <a href="xboole_0.html#V1" title="XBOOLE_0:attr.1">empty</a>   <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a> <br/>  for <font color="Olive" title="b3">F</font> being    <a href="group_20.html#M1" title="GROUP_20:mode.1">Subgroup-Family</a> of <font color="Olive" title="b2">I</font>,<font color="Olive" title="b1">G</font> holds <br/> ( <font color="Olive" title="b1">G</font> <a href="group_23.html#R1" title="GROUP_23:pred.1">is_internal_product_of</a> <font color="Olive" title="b3">F</font> iff <font color="Olive" title="b1">G</font> is  <a href="struct_0.html#V7" title="STRUCT_0:attr.7">trivial</a>  )</div></div>
