OAI/RingTheory/DirectFiniteness/CycleFactorization.lean
5 declarations, 0 contain sorry, 0 declared as axioms
- lemma
OAI.KaplanskyCounterexample.Planar.sameCycle_map_quotientline 16 - lemma
OAI.KaplanskyCounterexample.Planar.swap_cycles_card_leline 22 - lemma
OAI.KaplanskyCounterexample.Planar.cycles_card_leline 48 - lemma
OAI.KaplanskyCounterexample.Planar.cycles_one_cardline 51 - lemma
OAI.KaplanskyCounterexample.Planar.exists_cycle_factorizationline 60Source documentation
A minimal transposition factorization, with each transposition contained in one of the original cycles.
lemma exists_cycle_factorization (p : Perm α) : ∃ l : List (α × α), (l.map fun ab => swap ab.1 ab.2).prod = p ∧ l.length + Nat.card (Cycles p) = Fintype.card α ∧ ∀ ab ∈ l, ab.1 ≠ ab.2 ∧ p.SameCycle ab.1 ab.2 := by …