| Step | Hyp | Ref | Expression | 
						
							| 1 |  | uhgrf.v |  |-  V = ( Vtx ` G ) | 
						
							| 2 |  | uhgrf.e |  |-  E = ( iEdg ` G ) | 
						
							| 3 |  | uhgreq12g.w |  |-  W = ( Vtx ` H ) | 
						
							| 4 |  | uhgreq12g.f |  |-  F = ( iEdg ` H ) | 
						
							| 5 | 1 2 | isuhgr |  |-  ( G e. X -> ( G e. UHGraph <-> E : dom E --> ( ~P V \ { (/) } ) ) ) | 
						
							| 6 | 5 | adantr |  |-  ( ( G e. X /\ H e. Y ) -> ( G e. UHGraph <-> E : dom E --> ( ~P V \ { (/) } ) ) ) | 
						
							| 7 | 6 | adantr |  |-  ( ( ( G e. X /\ H e. Y ) /\ ( V = W /\ E = F ) ) -> ( G e. UHGraph <-> E : dom E --> ( ~P V \ { (/) } ) ) ) | 
						
							| 8 |  | simpr |  |-  ( ( V = W /\ E = F ) -> E = F ) | 
						
							| 9 | 8 | dmeqd |  |-  ( ( V = W /\ E = F ) -> dom E = dom F ) | 
						
							| 10 |  | pweq |  |-  ( V = W -> ~P V = ~P W ) | 
						
							| 11 | 10 | difeq1d |  |-  ( V = W -> ( ~P V \ { (/) } ) = ( ~P W \ { (/) } ) ) | 
						
							| 12 | 11 | adantr |  |-  ( ( V = W /\ E = F ) -> ( ~P V \ { (/) } ) = ( ~P W \ { (/) } ) ) | 
						
							| 13 | 8 9 12 | feq123d |  |-  ( ( V = W /\ E = F ) -> ( E : dom E --> ( ~P V \ { (/) } ) <-> F : dom F --> ( ~P W \ { (/) } ) ) ) | 
						
							| 14 | 3 4 | isuhgr |  |-  ( H e. Y -> ( H e. UHGraph <-> F : dom F --> ( ~P W \ { (/) } ) ) ) | 
						
							| 15 | 14 | adantl |  |-  ( ( G e. X /\ H e. Y ) -> ( H e. UHGraph <-> F : dom F --> ( ~P W \ { (/) } ) ) ) | 
						
							| 16 | 15 | bicomd |  |-  ( ( G e. X /\ H e. Y ) -> ( F : dom F --> ( ~P W \ { (/) } ) <-> H e. UHGraph ) ) | 
						
							| 17 | 13 16 | sylan9bbr |  |-  ( ( ( G e. X /\ H e. Y ) /\ ( V = W /\ E = F ) ) -> ( E : dom E --> ( ~P V \ { (/) } ) <-> H e. UHGraph ) ) | 
						
							| 18 | 7 17 | bitrd |  |-  ( ( ( G e. X /\ H e. Y ) /\ ( V = W /\ E = F ) ) -> ( G e. UHGraph <-> H e. UHGraph ) ) |