# Revision history [back]

The problem is with the file extension.

Use the file extension .sage.

For example, call your file something.sage.

Then type

sage: load('something.sage')


and check that your matrices have been defined correctly.

sage: d0
[1 0 0 0]
[0 1 1 0]
[1 0 0 0]
[0 1 1 0]
sage: d1
[ 0  0  0  0]
[-1  0  1  0]
[-1  0  1  0]
[ 0 -1  0  1]