def ur.r43
import bend-osdev-u32@0.1.0.0/PROOF.bend as PROOFimport Base
import bend-osdev-u32@0.1.0.0/LAWS.bend as Laws
2211def ur.r43(+x0: Nat, +x1: Nat) -> {Nat.add(x0, x1) == Nat.add(x1, x0) : Nat}:
2212 %Equal.sym(Nat, Nat.add(x0, x1), Nat.add(x1, x0), Equal.sym(Nat, Nat.add(x1, x0), Nat.add(x0, x1), Laws.nat_add_comm(x1, x0))) : {_ == Nat.add(x1, x0) : Nat}
2213 {==}