proposition: Lemma tuto_pair_eqP : forall T1 T2, Equality.axiom (@pair_eq T1 T2).
proof: Proof. move=> T1 T2 [u1 u2] [v1 v2] /=. apply: (iffP andP) => [[]|[<- <-]] //. by do 2!move/eqP->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype tuple finset)