Metamath Proof Explorer


Theorem uhgredgn0

Description: An edge of a hypergraph is a nonempty subset of vertices. (Contributed by AV, 28-Nov-2020)

Ref Expression
Assertion uhgredgn0 ( ( 𝐺 ∈ UHGraph ∧ 𝐸 ∈ ( Edg ‘ 𝐺 ) ) → 𝐸 ∈ ( 𝒫 ( Vtx ‘ 𝐺 ) ∖ { ∅ } ) )

Proof

Step Hyp Ref Expression
1 edgval ⊢ ( Edg ‘ 𝐺 ) = ran ( iEdg ‘ 𝐺 )
2 eqid ⊢ ( Vtx ‘ 𝐺 ) = ( Vtx ‘ 𝐺 )
3 eqid ⊢ ( iEdg ‘ 𝐺 ) = ( iEdg ‘ 𝐺 )
4 2 3 uhgrf ⊢ ( 𝐺 ∈ UHGraph → ( iEdg ‘ 𝐺 ) : dom ( iEdg ‘ 𝐺 ) ⟶ ( 𝒫 ( Vtx ‘ 𝐺 ) ∖ { ∅ } ) )
5 4 frnd ⊢ ( 𝐺 ∈ UHGraph → ran ( iEdg ‘ 𝐺 ) ⊆ ( 𝒫 ( Vtx ‘ 𝐺 ) ∖ { ∅ } ) )
6 1 5 eqsstrid ⊢ ( 𝐺 ∈ UHGraph → ( Edg ‘ 𝐺 ) ⊆ ( 𝒫 ( Vtx ‘ 𝐺 ) ∖ { ∅ } ) )
7 6 sselda ⊢ ( ( 𝐺 ∈ UHGraph ∧ 𝐸 ∈ ( Edg ‘ 𝐺 ) ) → 𝐸 ∈ ( 𝒫 ( Vtx ‘ 𝐺 ) ∖ { ∅ } ) )