Question

Boolean algebra:
x or x = x (identity)
What about ~x or ~x, is it ~x?

Answer 1

For example, does A'A'C'D' equal to A'C'D' ?

Answer 2

What about ~x or ~x, is it ~x? Yes. it simplifies to ~x
does A'A'C'D' equal to A'C'D' ?

I think A'A' means A' ^ A' (A' and A')
but anything anded with itself is itself: 1 ^ 1 =1 0 ^ 0 = 0
so A'A'C'D' = A'C'D'