OAI/GroupTheory/Thompson/BasicPartition.lean
19 declarations, 0 contain sorry, 0 declared as axioms
Finite partitions into basic dyadic intervals
Closed cells cover the unit interval; their open interiors are disjoint. Restriction is the actual inverse image of the cell set under affine insertion.
- structure
OAI.ThompsonNonamenability.BasicPartitionline 21 - theorem
OAI.ThompsonNonamenability.BasicPartition.extline 30 - def
OAI.ThompsonNonamenability.BasicPartition.cellCountline 36 - def
OAI.ThompsonNonamenability.BasicPartition.Respectsline 39Source documentation
The interval is exactly covered by partition cells contained in it.
def Respects (T : BasicPartition) (I : BasicInterval) : Prop := …
Mentions: OAI.ThompsonNonamenability.BasicPartition, OAI.ThompsonNonamenability.BasicInterval
- theorem
OAI.ThompsonNonamenability.BasicPartition.cellCount_posline 42 - theorem
OAI.ThompsonNonamenability.BasicPartition.respects_of_memline 46 - theorem
OAI.ThompsonNonamenability.BasicPartition.interiors_overlap_of_mem_interior_mem_carrierline 51 - theorem
OAI.ThompsonNonamenability.BasicPartition.eq_of_mem_interior_mem_carrierline 65Source documentation
At an interior point, even membership in another closed cell forces equality.
theorem eq_of_mem_interior_mem_carrier (T : BasicPartition) {I J : BasicInterval} (hI : I ∈ T.cells) (hJ : J ∈ T.cells) {x : ℝ} (hxI : x ∈ I.interior) (hxJ : x ∈ J.carrier) : I = J := by …Mentions: OAI.ThompsonNonamenability.BasicPartition, OAI.ThompsonNonamenability.BasicInterval
- theorem
OAI.ThompsonNonamenability.BasicPartition.respects_iffline 73Source documentation
Equivalent geometric crossing condition, including the endpoint argument.
theorem respects_iff (T : BasicPartition) (I : BasicInterval) : T.Respects I ↔ ∀ K ∈ T.cells, (K.interior ∩ I.interior).Nonempty → K.Contained I := by …Mentions: OAI.ThompsonNonamenability.BasicPartition, OAI.ThompsonNonamenability.BasicInterval
- theorem
OAI.ThompsonNonamenability.BasicPartition.respects_of_mesh_ltline 108Source documentation
A sufficiently fine actual partition respects the specified basic interval.
theorem respects_of_mesh_lt (T : BasicPartition) (I : BasicInterval) (hmesh : ∀ K ∈ T.cells, K.length < I.length) : T.Respects I := by …Mentions: OAI.ThompsonNonamenability.BasicPartition, OAI.ThompsonNonamenability.BasicInterval
- def
OAI.ThompsonNonamenability.BasicPartition.restrictCellsline 120Source documentation
Affinely normalized cells. Membership is exactly membership after insertion.
def restrictCells (T : BasicPartition) (I : BasicInterval) : Finset BasicInterval := …
Mentions: OAI.ThompsonNonamenability.BasicPartition, OAI.ThompsonNonamenability.BasicInterval
- theorem
OAI.ThompsonNonamenability.BasicPartition.mem_restrictCellsline 124 - def
OAI.ThompsonNonamenability.BasicPartition.restrictline 129Source documentation
The genuine partition obtained by restriction and affine normalization.
def restrict (T : BasicPartition) (I : BasicInterval) (h : T.Respects I) : BasicPartition where …Mentions: OAI.ThompsonNonamenability.BasicPartition, OAI.ThompsonNonamenability.BasicInterval
- theorem
OAI.ThompsonNonamenability.BasicPartition.mem_restrict_cellsline 153 - theorem
OAI.ThompsonNonamenability.BasicPartition.restrict_proof_irrelline 158 - theorem
OAI.ThompsonNonamenability.BasicPartition.restrict_cellCount_eq_filter_cardline 162 - theorem
OAI.ThompsonNonamenability.BasicPartition.restrict_cellCount_ltline 173 - theorem
OAI.ThompsonNonamenability.BasicPartition.restrict_respectsline 190 - theorem
OAI.ThompsonNonamenability.BasicPartition.restrict_restrictline 207