diff options
Diffstat (limited to 'Nominal/Permutations.lean')
| -rw-r--r-- | Nominal/Permutations.lean | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Nominal/Permutations.lean b/Nominal/Permutations.lean index a2f8d56..0d6b81c 100644 --- a/Nominal/Permutations.lean +++ b/Nominal/Permutations.lean @@ -158,6 +158,12 @@ lemma swap_apply_left (a b : X) : ⸨a, b⸩ a = b := by lemma swap_apply_right (a b : X) : ⸨a, b⸩ b = a := by simp [swap] +/-- Lifting of Equiv.swap_inv to finite permutations. -/ +@[simp] +lemma swap_inv (a b : X) : ⸨a, b⸩⁻¹ = ⸨a, b⸩ := by + apply ext + simp [swap] + end FPerm example : FPerm ℕ := ⸨1, 2⸩ * ⸨3, 4⸩ * ⸨2, 3⸩ |