 compute the roots of a quadratic equation with real
  coefficients.

</PRE>
<A name="Specification"><B><FONT SIZE="+1">Specification</FONT></B></A>
<PRE>
      SUBROUTINE MC01VD( A, B, C, Z1RE, Z1IM, Z2RE, Z2IM, INFO )
C     .. Scalar Arguments ..
      INTEGER           INFO
      DOUBLE PRECISION  A, B, C, Z1IM, Z1RE, Z2IM, Z2RE

</PRE>
<A name="Arguments"><B><FONT SIZE="+1">Arguments</FONT></B></A>
<P>

</PRE>
<B>Input/Output Parameters</B>
<PRE>
  A       (input) DOUBLE PRECISION
          The value of