import logic open tactic inhabited namespace foo inductive sum (A : Type) (B : Type) : Type := inl : A → sum A B, inr : B → sum A B theorem inl_inhabited {A : Type} (B : Type) (H : inhabited A) : inhabited (sum A B) := inhabited.destruct H (λ a, inhabited.mk (sum.inl B a)) theorem inr_inhabited (A : Type) {B : Type} (H : inhabited B) : inhabited (sum A B) := inhabited.destruct H (λ b, inhabited.mk (sum.inr A b)) infixl `..`:100 := append definition my_tac := repeat (trace "iteration"; state; ( apply @inl_inhabited; trace "used inl" .. apply @inr_inhabited; trace "used inr" .. apply @num_inhabited; trace "used num")) ; now tactic_hint [inhabited] my_tac theorem T : inhabited (sum false num) end foo