th a new constant c.  We could also infer b(y)=c, but
that will come by other inference mechanisms.
<p>
If new_sn == INT_MAX, a new symbol will be generated; otherwise,
new_sn will be used as the symbol number of the new symbol.
<A NAME="orient_equalities"></A><HR><PRE><B>void orient_equalities(Topform c, BOOL allow_flips);
</B></PRE>For each equality literal (positive or negative) of Topform c,
compare the arguments; if the left is greater, mark the
atom as oriented, and if the the right is greater, flip t