State in each case whether A ⊂ B or A ⊄ B.
A = {x : xϵZ, x2 = 1}, B = {x : x ϵ N, x2 = 1}
A ⊄ B
Explanation: we have, A = { -1,1} and B={1}
Since, -1∈A and -1∉B thus A ⊄ B .