(** Addition *)

Notation plus := Nat.add (only parsing).Infix "+" := Nat.add : nat_scope.Definition f_equal2_plus := f_equal2 plus.Definition f_equal2_nat := f_equal2 (A1:=nat) (A2:=nat).

Lemma plus_n_Sm : forall n m:nat, S (n + m) = n + S m.