
  To apply a special similarity transformation to a system given as
  a triple (A,B,C),

     A &lt;-- P * A * P,  B &lt;-- P * B,  C &lt;-- C * P,

  where P is a matrix with 1 on the secondary diagonal, and with 0
  in the other entries.

</PRE>
<A name="Specification"><B><FONT SIZE="+1">Specification</FONT></B></A>
<PRE>
      SUBROUTINE TB01YD( N, M, P, A, LDA, B, LDB, C, LDC, INFO )
C     .. Scalar Arguments ..
      INTEGER            INFO, LDA, LDB, LDC, M, N, P
C     .. Array Arguments ..
      DOU