intros. f_equal.
(* Goal in v8.5: f v = g v Goal in v8.4: v = v -> f v = g v Expected: f = g *)
Admitted.
intros. f_equal.
(* In both v8.4 And v8.5 Goal 1: v = u -> f v = g u Goal 2: v = u  Expected Goal 1: f = g Expected Goal 2: v = u *)
Admitted.

Lemma test3 :
forall (v : nat) (u : list nat) (f : nat -> nat) (g : list nat -> nat),
f v = g u.