-- example : 0 < 2 := Nat.lt_trans Nat.zero_lt_one (Nat.lt_succ_self _) --^ $/lean/plainTermGoal --^ $/lean/plainTermGoal --^ $/lean/plainTermGoal --^ $/lean/plainTermGoal --^ $/lean/plainTermGoal example : Option Unit := do let y : Int ← none let x := Nat.zero --^ $/lean/plainTermGoal return () example (m n : Nat) : m < n := Nat.lt_trans _ _ --^ $/lean/plainTermGoal example : True := sorry --^ $/lean/plainTermGoal example : ∀ n, n < n + 42 := fun n => Nat.lt_of_le_of_lt (Nat.le_add_right n 41) (Nat.lt_succ_self _) --^ $/lean/plainTermGoal --^ $/lean/plainTermGoal example : ∀ n, n < 1 + n := by intro n rw [Nat.add_comm] --^ $/lean/plainTermGoal exact Nat.lt_succ_self _ --^ $/lean/plainTermGoal #check fun (n m : Nat) => m --^ $/lean/plainTermGoal