OAI/NumberTheory/TwoPoint/Walks/ForestPathCode.lean

GitHub source file

3 declarations, 0 contain sorry, 0 declared as axioms

An endpoint pair in a numbered forest recovers an entire non-reversing walk.

  1. theorem OAI.TwoPointCorrelations.forest_path_support_identified line 14

    Source documentation

    The support of a path is transported exactly by a graph isomorphism.

    theorem forest_path_support_identified (e : G ≃g H) (hH : H.IsAcyclic)
        {a b : V} (p : G.Walk a b) (q : H.Walk (e a) (e b))
        (hp : p.IsPath) (hq : q.IsPath) : p.support.map e = q.support := by
    …
  2. theorem OAI.TwoPointCorrelations.represented_walk_same_code line 26

    Source documentation

    Equal shape and equal endpoint indices determine the same numbered walk, independently of the numerical realization of the graph.

    theorem represented_walk_same_code [DecidableEq V] [DecidableEq W]
        (t : BinaryTree V) (s : BinaryTree W)
        (ht : (forestNodes t).Nodup) (hc : ∀ v, v ∈ forestNodes t)
        (hs : (forestNodes s).Nodup) (hd : ∀ w, w ∈ forestNodes s)
        (hG : ∀ a b, forestAdjacent t a b ↔ G.Adj a b)
        (hH : ∀ a b, forestAdjacent s a b ↔ H.Adj a b)
        (hshape : t.map (fun _ => ()) = s.map (fun _ => ()))
        (hGa : G.IsAcyclic) (hHa : H.IsAcyclic)
        {a b : V} (p : G.Walk a b)
        (q : H.Walk (forestShapeEquiv t s ht hc hs hd hshape a)
          (forestShapeEquiv t s ht hc hs hd hshape b))
        (hp : List.IsChain (· ≠ ·) p.edges) (hq : List.IsChain (· ≠ ·) q.edges) :
    …

    Mentions: OAI.TwoPointCorrelations.forestNodes, OAI.TwoPointCorrelations.forestAdjacent, OAI.TwoPointCorrelations.forestShapeEquiv

  3. theorem OAI.TwoPointCorrelations.represented_walk_same_endpoints line 52

    Source documentation

    Endpoint indices suffice; the graphs may have different vertex types.

    theorem represented_walk_same_endpoints [DecidableEq V] [DecidableEq W]
        (t : BinaryTree V) (s : BinaryTree W)
        (ht : (forestNodes t).Nodup) (hc : ∀ v, v ∈ forestNodes t)
        (hs : (forestNodes s).Nodup) (hd : ∀ w, w ∈ forestNodes s)
        (hG : ∀ a b, forestAdjacent t a b ↔ G.Adj a b)
        (hH : ∀ a b, forestAdjacent s a b ↔ H.Adj a b)
        (hshape : t.map (fun _ => ()) = s.map (fun _ => ()))
        (hGa : G.IsAcyclic) (hHa : H.IsAcyclic)
        {a b : V} {c d : W} (p : G.Walk a b) (q : H.Walk c d)
        (hp : List.IsChain (· ≠ ·) p.edges) (hq : List.IsChain (· ≠ ·) q.edges)
        (ha : (forestNodes t).idxOf a = (forestNodes s).idxOf c)
        (hb : (forestNodes t).idxOf b = (forestNodes s).idxOf d) :
    …

    Mentions: OAI.TwoPointCorrelations.forestNodes, OAI.TwoPointCorrelations.forestAdjacent