diff --git a/src/algebra/field.lean b/src/algebra/field.lean index d2b4725ff0a1a..4a3e9d4703a39 100644 --- a/src/algebra/field.lean +++ b/src/algebra/field.lean @@ -19,6 +19,8 @@ instance division_ring.to_domain [s : division_ring α] : domain α := division_ring.mul_ne_zero (mt or.inl hn) (mt or.inr hn) h ..s } +@[simp] theorem inv_one [division_ring α] : (1⁻¹ : α) = 1 := by rw [inv_eq_one_div, one_div_one] + @[simp] theorem inv_inv' [discrete_field α] (x : α) : x⁻¹⁻¹ = x := if h : x = 0 then by rw [h, inv_zero, inv_zero] diff --git a/src/algebra/group_power.lean b/src/algebra/group_power.lean index 70c8c96eee483..28c8eb798405b 100644 --- a/src/algebra/group_power.lean +++ b/src/algebra/group_power.lean @@ -17,8 +17,6 @@ import data.int.basic data.list.basic universes u v variable {α : Type u} -@[simp] theorem inv_one [division_ring α] : (1⁻¹ : α) = 1 := by rw [inv_eq_one_div, one_div_one] - /-- The power operation in a monoid. `a^n = a*a*...*a` n times. -/ def monoid.pow [monoid α] (a : α) : ℕ → α | 0 := 1