Description: The set of edges of a multigraph is a subset of the set of unordered pairs of vertices. (Contributed by AV, 25-Nov-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | umgredgss | ⊢ ( 𝐺 ∈ UMGraph → ( Edg ‘ 𝐺 ) ⊆ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ ( ♯ ‘ 𝑥 ) = 2 } ) |
| 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 | umgrf | ⊢ ( 𝐺 ∈ UMGraph → ( iEdg ‘ 𝐺 ) : dom ( iEdg ‘ 𝐺 ) ⟶ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ ( ♯ ‘ 𝑥 ) = 2 } ) |
| 5 | 4 | frnd | ⊢ ( 𝐺 ∈ UMGraph → ran ( iEdg ‘ 𝐺 ) ⊆ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ ( ♯ ‘ 𝑥 ) = 2 } ) |
| 6 | 1 5 | eqsstrid | ⊢ ( 𝐺 ∈ UMGraph → ( Edg ‘ 𝐺 ) ⊆ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ ( ♯ ‘ 𝑥 ) = 2 } ) |