(** Since applying a theorem with hypotheses to some goal has the effect of generating as many subgoals as there are hypotheses for that theorem, we can apply [and_intro] to achieve the same effect as [split]. *)
(** **** Exercise: 2 stars (and_exercise)  *)
Example and_exercise :
forall n m : nat, n + m = 0 -> n = 0 /\ m = 0.
(** As usual, we can also destruct [H] right when we introduce it, instead of introducing and then destructing it: *)

(* Specifications: *)
Lemma and_example2' :
forall n m : nat, n = 0 /\ m = 0 -> n + m = 0.