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Mathlib.Combinatorics.SimpleGraph.Ends.Properties

Properties of the ends of graphs #

This file is meant to contain results about the ends of (locally finite connected) graphs.

theorem SimpleGraph.end_componentCompl_infinite {V : Type} (G : SimpleGraph V) (e : G.end) (K : (Finset V)ᵒᵖ) :

The componentCompls chosen by an end are all infinite.

instance SimpleGraph.compononentComplFunctor_nonempty_of_infinite {V : Type} (G : SimpleGraph V) [Infinite V] (K : (Finset V)ᵒᵖ) :
Nonempty (G.componentComplFunctor.obj K)
instance SimpleGraph.componentComplFunctor_finite {V : Type} (G : SimpleGraph V) [G.LocallyFinite] [Fact G.Preconnected] (K : (Finset V)ᵒᵖ) :
Finite (G.componentComplFunctor.obj K)
theorem SimpleGraph.nonempty_ends_of_infinite {V : Type} (G : SimpleGraph V) [G.LocallyFinite] [Fact G.Preconnected] [Infinite V] :
G.end.Nonempty

A locally finite preconnected infinite graph has at least one end.