proposition: Lemma le_succ_self (a : mynat) : a ≤ succ a.
proof: Proof. exact (le_succ a a (le_refl a)). Qed.
imports: Unicode.Utf8 Game.Mynat.Definition Game.Mynat.Add Game.Mynat.Mul Game.Mynat.Le Game.World.Addition Game.World.Multiplication Game.World.Proposition Game.World.AdvancedProposition Game.World.AdvancedAddition Game.World.AdvancedMultiplication