Metamath Proof Explorer


Theorem ushgrf

Description: The edge function of an undirected simple hypergraph is a one-to-one function into the power set of the set of vertices. (Contributed by AV, 9-Oct-2020)

Ref Expression
Hypotheses uhgrf.v ⊢ V = Vtx ⁡ G
uhgrf.e ⊢ E = iEdg ⁡ G
Assertion ushgrf ⊢ G ∈ USHGraph → E : dom ⁡ E ⟶ 1-1 𝒫 V ∖ ∅

Proof

Step Hyp Ref Expression
1 uhgrf.v ⊢ V = Vtx ⁡ G
2 uhgrf.e ⊢ E = iEdg ⁡ G
3 1 2 isushgr ⊢ G ∈ USHGraph → G ∈ USHGraph ↔ E : dom ⁡ E ⟶ 1-1 𝒫 V ∖ ∅
4 3 ibi ⊢ G ∈ USHGraph → E : dom ⁡ E ⟶ 1-1 𝒫 V ∖ ∅