Comment by foobar10000

It used to be the library one wrote to solve them at once - the solution being isomorphic that is, not the problems. I.e. given problems a b c d, f(a) solves a, g(b) solves b, … j(d) solves d - turns out if you can write a common function F instead of f g h j separately, then clearly F is isomorphic to f g h j under our constraints.

I guess in this case the morphism is the similar or same prompt to generate f g h j.