Module

Models.lean

Nyll.ValuedFieldTheory.Valuation.Topology.Models
2 declarations indexed from sourceView source ↗

Topological API for WithTopology

This file adds only the two topology lemmas used by valuation theory. The underlying type, topology, and basic API come directly from Mathlib. Algebraic structures needed on a particular topology-indexed copy are installed at that copy's owner rather than globally in the root WithTopology namespace.

Declarations

WithTopology.homeomorph

The canonical homeomorphism from Mathlib's topology-indexed copy to its underlying carrier equipped with the indexed topology.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

universe u v
namespace WithTopology
variable {X : Type u} {t : TopologicalSpace X}
def homeomorph {α : Type u} {topology : TopologicalSpace α} :
    @Homeomorph (WithTopology α topology) α
      (inferInstance : TopologicalSpace (WithTopology α topology)) topology where
  toEquiv := WithTopology.equiv α topology
  continuous_toFun := continuous_ofTopology topology
  continuous_invFun := continuous_toTopology topology
WithTopology.tendsto_nhds_iff

Convergence in a topology-indexed copy is convergence of the underlying points for the indexed topology.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

universe u v
namespace WithTopology
variable {X : Type u} {t : TopologicalSpace X}
theorem tendsto_nhds_iff {ι : Type v} {l : Filter ι}
    {f : ι → WithTopology X t} {x : WithTopology X t} :
    Filter.Tendsto f l (nhds x) ↔
      Filter.Tendsto (fun i => (f i).ofTopology) l
        (@nhds X t x.ofTopology) := by
  have h :=
    (homeomorph (α := X) (topology := t)).isEmbedding.tendsto_nhds_iff
    (f := f) (l := l) (y := x)
  exact h