| import Lean | |
| open Lean | |
| #eval [1,2,3,] | |
| #eval (2,3,) | |
| #eval [1,2,3,,] -- Errors, double trailing comma | |
| #eval (4,5,,,) -- ditto | |
| axiom zeroAdd (x : Nat) : 0 + x = x | |
| theorem rewrite_comma (x y z: Nat) (h₁ : 0 + x = y) (h₂ : 0 + y = z) : x = z := by | |
| rewrite [zeroAdd,] at *; | |
| subst x; | |
| subst y; | |
| exact rfl | |
| theorem simp_comma (x: Nat) : x = x := by | |
| simp [zeroAdd,] |