fact: Record Message := { msg_key: Key; msg_val: Val; msg_update: Update Val; msg_receiver: NId }.
imports: Coq(FunctionalExtensionality Arith Lia) Coq(Arith.Peano_dec Arith.Compare_dec) Coq(Relations.Relation_Operators) Coq(List) Chapar(Predefs)