sumed to be zero;
          = 'N';  no structure to mention.

  TRANA   CHARACTER*1
          Specifies the form of op( A ) as follows:
          = 'N':  op( A ) = A;
          = 'T':  op( A ) = A';
          = 'C':  op( A ) = A'.

  TRANB   CHARACTER*1
          Specifies the form of op( B ) as follows:
          = 'N':  op( B ) = B;
          = 'T':  op( B ) = B';
          = 'C':  op( B ) = B'.

  DIRECT  CHARACTER*1
          This is a dummy argument, which is reserved for future
          extensions of