import logic using tactic definition my_tac1 := apply @refl definition my_tac2 := repeat (apply @and_intro; assumption) tactic_hint my_tac1 tactic_hint my_tac2 theorem T1 {A : Type.{2}} (a : A) : a = a theorem T2 {a b c : Prop} (Ha : a) (Hb : b) (Hc : c) : a ∧ b ∧ c definition my_tac3 := fixpoint (λ f, [apply @or_intro_left; f | apply @or_intro_right; f | assumption]) tactic_hint [or] my_tac3 theorem T3 {a b c : Prop} (Hb : b) : a ∨ b ∨ c