fact: Definition fprod A1 A2 B1 B2 (f1 : A1 -> B1) (f2 : A2 -> B2) := fun (x : A1 * A2) => (f1 x.1, f2 x.2).
imports: Coq(ssreflect ssrbool ssrfun Eqdep) mathcomp(ssrnat seq eqtype choice fintype) pcm(options axioms)