new_frontend #check id fun x => x -- should fail def f (x : Nat) (g : Nat → Nat) := g x #check f 1 fun x => x -- should fail #check f 1 (fun x => x) #check id have True from ⟨⟩; this -- should fail #check 1 #check id (have True from ⟨⟩; this) #check 0 = have Nat from 1; this #check 0 = let x := 0; x variables (p q r : Prop) macro_rules `(¬ $p) => `(Not $p) #check p ↔ ¬ q #check True = ¬ False #check p ∧ ¬q #check ¬p ∧ q #check ¬p ↔ q #check ¬(p = q) #check ¬ p = q #check id ¬p #check Nat → ∀ (a : Nat), a = a