Tolong jelaskan mengenai f(f −1(B)) ⊆ B. dari Fungsi (matematika) dalam bahasa sunda

These are valid for arbitrary subsets A, A1 and A2 of the domain and arbitrary subsets B, B1 and B2 of the codomain.

The results relating images and preimages to the algebra of intersection and union work for any collections of subsets, not just for pairs of subsets.