| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ausgr.1 | ⊢ 𝐺  =  { 〈 𝑣 ,  𝑒 〉  ∣  𝑒  ⊆  { 𝑥  ∈  𝒫  𝑣  ∣  ( ♯ ‘ 𝑥 )  =  2 } } | 
						
							| 2 |  | usgredgss | ⊢ ( 𝐻  ∈  USGraph  →  ( Edg ‘ 𝐻 )  ⊆  { 𝑥  ∈  𝒫  ( Vtx ‘ 𝐻 )  ∣  ( ♯ ‘ 𝑥 )  =  2 } ) | 
						
							| 3 |  | fvex | ⊢ ( Vtx ‘ 𝐻 )  ∈  V | 
						
							| 4 |  | fvex | ⊢ ( Edg ‘ 𝐻 )  ∈  V | 
						
							| 5 | 1 | isausgr | ⊢ ( ( ( Vtx ‘ 𝐻 )  ∈  V  ∧  ( Edg ‘ 𝐻 )  ∈  V )  →  ( ( Vtx ‘ 𝐻 ) 𝐺 ( Edg ‘ 𝐻 )  ↔  ( Edg ‘ 𝐻 )  ⊆  { 𝑥  ∈  𝒫  ( Vtx ‘ 𝐻 )  ∣  ( ♯ ‘ 𝑥 )  =  2 } ) ) | 
						
							| 6 | 3 4 5 | mp2an | ⊢ ( ( Vtx ‘ 𝐻 ) 𝐺 ( Edg ‘ 𝐻 )  ↔  ( Edg ‘ 𝐻 )  ⊆  { 𝑥  ∈  𝒫  ( Vtx ‘ 𝐻 )  ∣  ( ♯ ‘ 𝑥 )  =  2 } ) | 
						
							| 7 | 2 6 | sylibr | ⊢ ( 𝐻  ∈  USGraph  →  ( Vtx ‘ 𝐻 ) 𝐺 ( Edg ‘ 𝐻 ) ) |