fact: Definition update_key {V: Set} (m: Key -> V) (k: Key) (v: V): Key -> V := fun (k': Key) => if (key_eq_dec k' k) then v else (m k).
imports: Coq(FunctionalExtensionality Arith Lia) Coq(Arith.Peano_dec Arith.Compare_dec) Coq(Relations.Relation_Operators) Coq(List) Chapar(Predefs)