fact: Definition equiv_flip `(P : A -> B -> Type) : (forall a b, P a b) <~> (forall b a, P a b) := Build_Equiv _ _ (@flip _ _ P) _.
imports: Basics.Overture Basics.Equivalences Basics.PathGroupoids Basics.Tactics Basics.Trunc Basics.Contractible Basics.Trunc (istrunc_forall)