. mata
: a=2,9,4\7,5,3\6,1,8

: b=I(3)

: a,b
       1   2   3   4   5   6
    +-------------------------+
  1 |  2   9   4   1   0   0  |
  2 |  7   5   3   0   1   0  |
  3 |  6   1   8   0   0   1  |
    +-------------------------+

: a\b
       1   2   3
    +-------------+
  1 |  2   9   4  |
  2 |  7   5   3  |
  3 |  6   1   8  |
  4 |  1   0   0  |
  5 |  0   1   0  |
  6 |  0   0   1  |
    +-------------+

: end