utput matrix of an equivalent reduced, possibly scaled
          (if EQUIL = 'S') system, used to check the properness.
          Otherwise, the array C is unchanged.

  LDC     INTEGER
          The leading dimension of the array C.  LDC &gt;= max(1,P).

  D       (input) DOUBLE PRECISION array, dimension (LDD,M)
          If JOBD = 'D' or JOBD = 'F', the leading P-by-M part of
          this array must contain the direct transmission matrix D.
          The array D is not referenced if JOBD = 'Z'.

  LDD 