diff options
Diffstat (limited to 'Nominal/Permutations.lean')
| -rw-r--r-- | Nominal/Permutations.lean | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Nominal/Permutations.lean b/Nominal/Permutations.lean index 1726ed7..a2f8d56 100644 --- a/Nominal/Permutations.lean +++ b/Nominal/Permutations.lean @@ -138,6 +138,11 @@ lemma swap_mul_self {a b : X} : ⸨a, b⸩ * ⸨a, b⸩ = 1 := by apply ext simp [swap] +/-- Lifting of Equiv.swap_comm to finite permutations. -/ +lemma swap_comm {a b : X} : ⸨a, b⸩ = ⸨b, a⸩ := by + apply ext + simp [swap, Equiv.swap_comm] + /-- Lifting of Equiv.swap_apply_of_ne_of_ne to finite permutations. -/ lemma swap_apply_of_ne_of_ne {a b c : X} : c ≠ a → c ≠ b → ⸨a, b⸩ c = c := by intro ha hb |