   The leading dimension of array C.  LDC &gt;= MAX(1,N).

</PRE>
<B>Tolerances</B>
<PRE>
  TOL     DOUBLE PRECISION
          The tolerance to be used to test for near singularity in
          the Sylvester equation. If the user sets TOL &gt; 0, then the
          given value of TOL is used as a lower bound for the
          reciprocal condition number; a matrix whose estimated
          condition number is less than 1/TOL is considered to be
          nonsingular. If the user sets TOL &lt;= 0, then a defa