OAI/GroupTheory/Thompson/OrderedChainKnots.lean
12 declarations, 0 contain sorry, 0 declared as axioms
Indexed knots of an ordered dyadic chain
An actual consecutive list of dyadic cells covering [0,1] gives a strictly
increasing subdivision indexed by that same list. The two endpoints of its
ith piece are exactly the endpoints of the ith listed cell.
- def
OAI.ThompsonNonamenability.GapChain.realKnotsline 23Source documentation
The initial endpoint followed by the right endpoints of the cells.
def realKnots : (a : ℝ) → (L : List BasicInterval) → Fin (L.length + 1) → ℝ | a, [], _ => a | a, I :: L, i => Fin.cases a (realKnots I.right L) i
Mentions: OAI.ThompsonNonamenability.BasicInterval
- theorem
OAI.ThompsonNonamenability.GapChain.realKnots_zeroline 27 - theorem
OAI.ThompsonNonamenability.GapChain.realKnots_succline 32Source documentation
The right knot of each indexed piece is its actual right endpoint.
theorem realKnots_succ (a : ℝ) (L : List BasicInterval) (i : Fin L.length) : realKnots a L i.succ = (L.get i).right := by …Mentions: OAI.ThompsonNonamenability.BasicInterval, OAI.ThompsonNonamenability.GapChain.realKnots
- theorem
OAI.ThompsonNonamenability.GapChain.realKnots_castSuccline 44Source documentation
The chain equalities identify each left knot with its listed cell.
theorem realKnots_castSucc {a b : ℝ} {L : List BasicInterval} (h : GapChain a b L) (i : Fin L.length) : realKnots a L i.castSucc = (L.get i).left := by …Mentions: OAI.ThompsonNonamenability.BasicInterval, OAI.ThompsonNonamenability.GapChain, OAI.ThompsonNonamenability.GapChain.realKnots
- theorem
OAI.ThompsonNonamenability.GapChain.realKnots_lastline 56 - theorem
OAI.ThompsonNonamenability.GapChain.strictMono_realKnotsline 64 - theorem
OAI.ThompsonNonamenability.GapChain.length_posline 71 - theorem
OAI.ThompsonNonamenability.GapChain.realKnots_mem_unitline 77 - theorem
OAI.ThompsonNonamenability.GapChain.isDyadic_realKnotsline 85 - structure
OAI.ThompsonNonamenability.ChainSubdivisionline 96Source documentation
A subdivision whose indexing agrees with an actual ordered cell list.
structure ChainSubdivision (L : List BasicInterval) where …
Mentions: OAI.ThompsonNonamenability.BasicInterval
- def
OAI.ThompsonNonamenability.GapChain.toSubdivisionline 111Source documentation
Construct all subdivision data from the chain equalities.
def toSubdivision {L : List BasicInterval} (h : GapChain 0 1 L) : ChainSubdivision L := by …Mentions: OAI.ThompsonNonamenability.BasicInterval, OAI.ThompsonNonamenability.GapChain, OAI.ThompsonNonamenability.ChainSubdivision
- theorem
OAI.ThompsonNonamenability.ChainSubdivision.mem_carrier_iffline 137Source documentation
Membership in an indexed cell is exactly membership between its knots.
theorem mem_carrier_iff {L : List BasicInterval} (s : ChainSubdivision L) (i : Fin L.length) (x : UnitInterval) : (x : ℝ) ∈ (L.get i).carrier ↔ s.knots i.castSucc ≤ x ∧ x ≤ s.knots i.succ := by …Mentions: OAI.ThompsonNonamenability.BasicInterval, OAI.ThompsonNonamenability.ChainSubdivision, OAI.ThompsonNonamenability.UnitInterval