The number of bases for the vector space Z2^2 is: 6
The bases are:
((0, 1), (1, 0))
((0, 1), (1, 1))
((1, 0), (0, 1))
((1, 0), (1, 1))
((1, 1), (0, 1))
((1, 1), (1, 0))