fact: Definition extends (Γ : Rel) (A1 A2 : Type) : Rel := mkRel (πl Γ × A1) (πr Γ × A2) (fun γa1 γa2 => Γ (nfst γa1) (nfst γa2)).
imports: Coq(ssreflect ssrfun ssrbool) Coq(Relation_Definitions Morphisms) Mon(SPropBase) Relational(Category RelativeMonads EnrichedSetting)