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 ) ∖ { ∅ } ) ) | 
| 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 ) ∖ { ∅ } ) ) |