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<div><span class="kw">theorem </span><a NAME="T21"><span class="comment"><font color="firebrick">:: YELLOW_2:21</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">L</font> being   non  <a href="struct_0.html#V2" title="STRUCT_0:attr.2">empty</a>   <a href="orders_2.html#L1" title="ORDERS_2:struct.1">RelStr</a>  holds   <a href="struct_0.html#K3" title="STRUCT_0:func.3">id</a> <font color="Olive" title="b1">L</font> is  <a href="quantal1.html#V11" title="QUANTAL1:attr.11">idempotent</a> </div></div>
