16 lines
454 B
Lean4
16 lines
454 B
Lean4
import Game.MyNat.Definition
|
||
import Mathlib.Tactic
|
||
|
||
namespace MyNat
|
||
|
||
-- KB note: I have not thought about simp at all and perhaps this
|
||
-- comes from some earlier NNG3 port?
|
||
attribute [-simp] MyNat.succ.injEq
|
||
-- example (a b : ℕ) (h : (succ a) = b) : succ (succ a) = succ b := by
|
||
-- simp
|
||
-- sorry
|
||
|
||
theorem succ_inj (a b : ℕ) : succ a = succ b → a = b := by rintro ⟨h⟩; rfl
|
||
|
||
theorem zero_ne_succ (a : ℕ) : 0 ≠ succ a := by rintro ⟨h⟩
|