Dev/MonadicDependence/WeaklySparseMonDepIsNowhereDense/Contract.lean
1import Catalog.Sparsity.Preliminaries.Contract
2import Dev.MonadicDependence.WeaklySparse.Contract
3import Dev.MonadicDependence.MonadicDependence.Contract
4import Dev.MonadicDependence.NowhereDense.Contract
5
6namespace Dev.MonadicDependence.WeaklySparseMonDepIsNowhereDense
7
8open Catalog.Sparsity.Preliminaries
9open Dev.MonadicDependence.WeaklySparse
10open Dev.MonadicDependence.MonadicDependence
11open Dev.MonadicDependence.NowhereDense
12
13/-- Mählmann Lemma 13.7. If a graph class `C` is weakly sparse
14(`Dev.MonadicDependence.WeaklySparse.IsWeaklySparse`) and monadically
15dependent (`Dev.MonadicDependence.MonadicDependence.IsMonadicallyDependent`),
16then it is nowhere dense in the local sense of
17`Dev.MonadicDependence.NowhereDense.IsNowhereDense`. -/
18axiom weaklySparseMonDepIsNowhereDense (C : GraphClass) :
19 IsWeaklySparse C → IsMonadicallyDependent C → IsNowhereDense C
20
21end Dev.MonadicDependence.WeaklySparseMonDepIsNowhereDense
22