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| author | Hannes Schulze <haschu0103@outlook.de> | 2025-10-25 01:07:56 +0200 |
|---|---|---|
| committer | Hannes Schulze <haschu0103@outlook.de> | 2025-10-25 01:07:56 +0200 |
| commit | c3700706466cb8fb9ed287ea066b656caacdc9c7 (patch) | |
| tree | 1c999654b8d989e90e697040a9c1d3a2a700c2ac /Nominal/Permutations.lean | |
| parent | 6df3f662f0f23e837b70ef1f4a8b8dde4a7aa521 (diff) | |
start working on alpha equivalence proofs
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 b8d510e..62d7470 100644 --- a/Nominal/Permutations.lean +++ b/Nominal/Permutations.lean @@ -133,6 +133,11 @@ lemma mul_swap_eq_swap_mul {π : FPerm X} {a b : X} : π * ⸨a, b⸩ = ⸨π a, apply ext apply Equiv.mul_swap_eq_swap_mul +/-- Lifting of Equiv.swap_mul_self to finite permutations. -/ +lemma swap_mul_self {a b : X} : ⸨a, b⸩ * ⸨a, b⸩ = 1 := by + apply ext + simp [swap] + /-- If c is not equal to a or b, then (a b) leaves c unchanged. -/ lemma swap_neq {a b c : X} : c ≠ a → c ≠ b → ⸨a, b⸩ c = c := by intro ha hb |