Exercise
What are the residue classes of congruence modulo ({2, X2}) in Z/4Z[X]?
0, 1
0, 1, X
0, 1, X, X + 1
No, X is not congruent to 0 or 1.
No, X + 1 is not congruent to 0, 1, or X.
Yes.
Exercise
What are the residue classes of congruence modulo ({2, X2}) in Z/4Z[X]?
0, 1
0, 1, X
0, 1, X, X + 1