def tr.add_zero
import bend-osdev-cipher-modes@0.1.0.0/PROOF.bend as PROOFimport Base
889def tr.add_zero(+a: Nat) -> {Nat.add(a, 0n) == a : Nat}:
890 match a:
891 case 0n:
892 {==}
893 case 1n+q:
894 Equal.cong(Nat, Nat, x => 1n+x, Nat.add(q, 0n), q, tr.add_zero(q))