| Step | Hyp | Ref | Expression | 
						
							| 1 |  | eqid | ⊢ ( Vtx ‘ 𝐺 )  =  ( Vtx ‘ 𝐺 ) | 
						
							| 2 |  | eqid | ⊢ ( iEdg ‘ 𝐺 )  =  ( iEdg ‘ 𝐺 ) | 
						
							| 3 | 1 2 | ushgrf | ⊢ ( 𝐺  ∈  USHGraph  →  ( iEdg ‘ 𝐺 ) : dom  ( iEdg ‘ 𝐺 ) –1-1→ ( 𝒫  ( Vtx ‘ 𝐺 )  ∖  { ∅ } ) ) | 
						
							| 4 |  | f1f | ⊢ ( ( iEdg ‘ 𝐺 ) : dom  ( iEdg ‘ 𝐺 ) –1-1→ ( 𝒫  ( Vtx ‘ 𝐺 )  ∖  { ∅ } )  →  ( iEdg ‘ 𝐺 ) : dom  ( iEdg ‘ 𝐺 ) ⟶ ( 𝒫  ( Vtx ‘ 𝐺 )  ∖  { ∅ } ) ) | 
						
							| 5 | 3 4 | syl | ⊢ ( 𝐺  ∈  USHGraph  →  ( iEdg ‘ 𝐺 ) : dom  ( iEdg ‘ 𝐺 ) ⟶ ( 𝒫  ( Vtx ‘ 𝐺 )  ∖  { ∅ } ) ) | 
						
							| 6 | 1 2 | isuhgr | ⊢ ( 𝐺  ∈  USHGraph  →  ( 𝐺  ∈  UHGraph  ↔  ( iEdg ‘ 𝐺 ) : dom  ( iEdg ‘ 𝐺 ) ⟶ ( 𝒫  ( Vtx ‘ 𝐺 )  ∖  { ∅ } ) ) ) | 
						
							| 7 | 5 6 | mpbird | ⊢ ( 𝐺  ∈  USHGraph  →  𝐺  ∈  UHGraph ) |