OAI/NumberTheory/DukePrimeDegree/Geometry/RootSourceOrder.lean
1 declarations, 0 contain sorry, 0 declared as axioms
A root graph without two consecutive edges admits a source ordering
- theorem
OAI.DukePrimeDegree.exists_source_orderline 15Source documentation
Put targets before sources. This is the only finite ordering fact needed when the commutator theorem rules out two consecutive positive roots.
theorem exists_source_order (n : ℕ) (r : Fin n → Fin n → Prop) (hchain : ∀ a b c, r a b → r b c → False) : ∃ e : Equiv.Perm (Fin n), ∀ i j, r i j → e j < e i := by …