Section FuncEq.
Variables (A1 A2 A3 A4 A5 A6 A7 B : Type).
Proof using. intros. subst. auto. Qed.

Lemma args_eq_2 : forall (f:A1->A2->B) x1 y1 x2 y2,
x1 = y1 -> x2 = y2 ->
f x1 x2 = f y1 y2.