[texhax] help

[maryh.williams at murraystate.edu]

I have been looking for a very long time onhow to create a block matrix. I 
have a 10 by 10 matrix wit entries down the diagonal and above and below te 
diagonal. The rest are 0's and i wanted to put a big zero in the lower and 
upper triangles of the matrix. If you can give me any help then I would 
greatly appreciate it!

  Thanks!
Molly Williams