ex-arg gather-arg truth)</tt><br />Find the first gaf assertion such that:<br /><code></code>(a) the assertion is in one of the microtheories in the list MTS<br /><code></code>(b) if TRUTH is non-nil, the assertion has TRUTH as its truth value<br /><code></code>(c) PRED is the predicate used.<br /><code></code>(d) TERM is the term in the INDEX-ARG position.<br /><code></code>Return the term in the GATHER-ARG position if such an assertion exists.<br /><code></code>Otherwise, return NIL.<br />TERM must satisf