SLASY2 solves for the N1 by N2 matrix X, 1 <= N1,N2 <= 2, in

        op(TL)*X + ISGN*X*op(TR) = SCALE*B,

 where TL is N1 by N1, TR is N2 by N2, B is N1 by N2, and ISGN = 1 or
 -1.  op(T) = T or T**T, where T**T denotes the transpose of T.

          LTRANL is LOGICAL
          On entry, LTRANL specifies the op(TL):
             = .FALSE., op(TL) = TL,
             = .TRUE., op(TL) = TL**T.

          LTRANR is LOGICAL
          On entry, LTRANR specifies the op(TR):
            = .FALSE., op(TR) = TR,
            = .TRUE., op(TR) = TR**T.

          ISGN is INTEGER
          On entry, ISGN specifies the sign of the equation
          as described before. ISGN may only be 1 or -1.

          N1 is INTEGER
          On entry, N1 specifies the order of matrix TL.
          N1 may only be 0, 1 or 2.

          N2 is INTEGER
          On entry, N2 specifies the order of matrix TR.
          N2 may only be 0, 1 or 2.

          TL is REAL array, dimension (LDTL,2)
          On entry, TL contains an N1 by N1 matrix.

          LDTL is INTEGER
          The leading dimension of the matrix TL. LDTL >= max(1,N1).

          TR is REAL array, dimension (LDTR,2)
          On entry, TR contains an N2 by N2 matrix.

          LDTR is INTEGER
          The leading dimension of the matrix TR. LDTR >= max(1,N2).

          B is REAL array, dimension (LDB,2)
          On entry, the N1 by N2 matrix B contains the right-hand
          side of the equation.

          LDB is INTEGER
          The leading dimension of the matrix B. LDB >= max(1,N1).

          SCALE is REAL
          On exit, SCALE contains the scale factor. SCALE is chosen
          less than or equal to 1 to prevent the solution overflowing.

          X is REAL array, dimension (LDX,2)
          On exit, X contains the N1 by N2 solution.

          LDX is INTEGER
          The leading dimension of the matrix X. LDX >= max(1,N1).

          XNORM is REAL
          On exit, XNORM is the infinity-norm of the solution.

          INFO is INTEGER
          On exit, INFO is set to
             0: successful exit.
             1: TL and TR have too close eigenvalues, so TL or
                TR is perturbed to get a nonsingular equation.
          NOTE: In the interests of speed, this routine does not
                check the inputs for errors.