OAI/Combinatorics/HoneycombChords/PathComponents.lean
11 declarations, 0 contain sorry, 0 declared as axioms
Paths and cycles in finite two-port graphs
Formalized from Critical honeycomb chords with prescribed boundary endpoints (OpenAI, September 26, 2026).
- lemma
OAI.CriticalHoneycomb.Transfer.PathComponents.ncard_neighborsline 22 - lemma
OAI.CriticalHoneycomb.Transfer.PathComponents.ports_reachableline 26 - lemma
OAI.CriticalHoneycomb.Transfer.PathComponents.path_neighbor_eqline 48 - lemma
OAI.CriticalHoneycomb.Transfer.PathComponents.path_closedline 74 - lemma
OAI.CriticalHoneycomb.Transfer.PathComponents.residual_isCyclesline 85 - theorem
OAI.CriticalHoneycomb.Transfer.PathComponents.path_and_cyclesline 130Source documentation
Every finite nonbranching two-port configuration is a path plus cycles. The path has no edge to the residual cycle graph.
theorem path_and_cycles {a b : V} (hab : a ≠ b) (ha : G.degree a = 1) (hb : G.degree b = 1) (other : ∀ v, v ≠ a → v ≠ b → G.degree v = 0 ∨ G.degree v = 2) : ∃ p : G.Walk a b, p.IsPath ∧ (G \ p.toSubgraph.spanningCoe).IsCycles ∧ ∀ v ∈ p.support, p.toSubgraph.neighborSet v = G.neighborSet v := by …Mentions: OAI.CriticalHoneycomb.Transfer.a, OAI.CriticalHoneycomb.Transfer.v
- def
OAI.CriticalHoneycomb.Transfer.FiniteConfigurations.portRelline 154Source documentation
The hard-wall two-port graph: the two exterior markers have only their prescribed incident edge; internal adjacency remains unchanged.
def portRel (R : α → α → Prop) (a b : α) : (α ⊕ Bool) → (α ⊕ Bool) → Prop | .inl x, .inl y => R x y | .inr false, .inl y | .inl y, .inr false => y=a | .inr true, .inl y | .inl y, .inr true => y=b | .inr _, .inr _ => False
Mentions: OAI.CriticalHoneycomb.Transfer.a
- lemma
OAI.CriticalHoneycomb.Transfer.FiniteConfigurations.chain_snoc_portsline 160 - lemma
OAI.CriticalHoneycomb.Transfer.FiniteConfigurations.chain_portsline 166 - lemma
OAI.CriticalHoneycomb.Transfer.FiniteConfigurations.list_all_inlline 183 - lemma
OAI.CriticalHoneycomb.Transfer.FiniteConfigurations.support_decompositionline 195