From elpi.apps Require Import tc.
Class A (n : nat).
Class B.
Instance a : A 0 := {}.
Lemma foo: forall x `{A x}, True -> B. Admitted.
Goal B.
refine (foo _ _).
(* Note: the subgoal True is put into the shelf, however, we expect it to be in the list of goal to treat *)
Fail auto.
Qed.