                                                     d
      P   (s) = P   (0) + P   (1) * s + . . . + P   (d) * s
       i,j       i,j       i,j                   i,j

  be the nonzero (i,j)-th element of the matrix polynomial P(s).

  Then P(i,j,k) corresponds to coefficient P   (k-1), k = 1,...,d+1.
                                            i,j
  For each nonzero element, the values i, j, and d are read as one
  record of the file NIN, and the values P(i,j,k), k = 1,...,d+1,
  are read as the following