A\B is all x in A but not in B
x not in A\B is all x in A&B or in B.
So, A\(A\B) is all x in A and in (A&B or B) so, it is all x in A&B ⊆ B
Sorry posted the wrong question earlier.
Let A and B be sets. Show that A \ (A \ B) ⊆ B.
1 answer