| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ov6g.1 |  |-  ( <. x , y >. = <. A , B >. -> R = S ) | 
						
							| 2 |  | ov6g.2 |  |-  F = { <. <. x , y >. , z >. | ( <. x , y >. e. C /\ z = R ) } | 
						
							| 3 |  | df-ov |  |-  ( A F B ) = ( F ` <. A , B >. ) | 
						
							| 4 |  | eqid |  |-  S = S | 
						
							| 5 |  | biidd |  |-  ( ( x = A /\ y = B ) -> ( S = S <-> S = S ) ) | 
						
							| 6 | 5 | copsex2g |  |-  ( ( A e. G /\ B e. H ) -> ( E. x E. y ( <. A , B >. = <. x , y >. /\ S = S ) <-> S = S ) ) | 
						
							| 7 | 4 6 | mpbiri |  |-  ( ( A e. G /\ B e. H ) -> E. x E. y ( <. A , B >. = <. x , y >. /\ S = S ) ) | 
						
							| 8 | 7 | 3adant3 |  |-  ( ( A e. G /\ B e. H /\ <. A , B >. e. C ) -> E. x E. y ( <. A , B >. = <. x , y >. /\ S = S ) ) | 
						
							| 9 | 8 | adantr |  |-  ( ( ( A e. G /\ B e. H /\ <. A , B >. e. C ) /\ S e. J ) -> E. x E. y ( <. A , B >. = <. x , y >. /\ S = S ) ) | 
						
							| 10 |  | eqeq1 |  |-  ( w = <. A , B >. -> ( w = <. x , y >. <-> <. A , B >. = <. x , y >. ) ) | 
						
							| 11 | 10 | anbi1d |  |-  ( w = <. A , B >. -> ( ( w = <. x , y >. /\ z = R ) <-> ( <. A , B >. = <. x , y >. /\ z = R ) ) ) | 
						
							| 12 | 1 | eqeq2d |  |-  ( <. x , y >. = <. A , B >. -> ( z = R <-> z = S ) ) | 
						
							| 13 | 12 | eqcoms |  |-  ( <. A , B >. = <. x , y >. -> ( z = R <-> z = S ) ) | 
						
							| 14 | 13 | pm5.32i |  |-  ( ( <. A , B >. = <. x , y >. /\ z = R ) <-> ( <. A , B >. = <. x , y >. /\ z = S ) ) | 
						
							| 15 | 11 14 | bitrdi |  |-  ( w = <. A , B >. -> ( ( w = <. x , y >. /\ z = R ) <-> ( <. A , B >. = <. x , y >. /\ z = S ) ) ) | 
						
							| 16 | 15 | 2exbidv |  |-  ( w = <. A , B >. -> ( E. x E. y ( w = <. x , y >. /\ z = R ) <-> E. x E. y ( <. A , B >. = <. x , y >. /\ z = S ) ) ) | 
						
							| 17 |  | eqeq1 |  |-  ( z = S -> ( z = S <-> S = S ) ) | 
						
							| 18 | 17 | anbi2d |  |-  ( z = S -> ( ( <. A , B >. = <. x , y >. /\ z = S ) <-> ( <. A , B >. = <. x , y >. /\ S = S ) ) ) | 
						
							| 19 | 18 | 2exbidv |  |-  ( z = S -> ( E. x E. y ( <. A , B >. = <. x , y >. /\ z = S ) <-> E. x E. y ( <. A , B >. = <. x , y >. /\ S = S ) ) ) | 
						
							| 20 |  | moeq |  |-  E* z z = R | 
						
							| 21 | 20 | mosubop |  |-  E* z E. x E. y ( w = <. x , y >. /\ z = R ) | 
						
							| 22 | 21 | a1i |  |-  ( w e. C -> E* z E. x E. y ( w = <. x , y >. /\ z = R ) ) | 
						
							| 23 |  | dfoprab2 |  |-  { <. <. x , y >. , z >. | ( <. x , y >. e. C /\ z = R ) } = { <. w , z >. | E. x E. y ( w = <. x , y >. /\ ( <. x , y >. e. C /\ z = R ) ) } | 
						
							| 24 |  | eleq1 |  |-  ( w = <. x , y >. -> ( w e. C <-> <. x , y >. e. C ) ) | 
						
							| 25 | 24 | anbi1d |  |-  ( w = <. x , y >. -> ( ( w e. C /\ z = R ) <-> ( <. x , y >. e. C /\ z = R ) ) ) | 
						
							| 26 | 25 | pm5.32i |  |-  ( ( w = <. x , y >. /\ ( w e. C /\ z = R ) ) <-> ( w = <. x , y >. /\ ( <. x , y >. e. C /\ z = R ) ) ) | 
						
							| 27 |  | an12 |  |-  ( ( w = <. x , y >. /\ ( w e. C /\ z = R ) ) <-> ( w e. C /\ ( w = <. x , y >. /\ z = R ) ) ) | 
						
							| 28 | 26 27 | bitr3i |  |-  ( ( w = <. x , y >. /\ ( <. x , y >. e. C /\ z = R ) ) <-> ( w e. C /\ ( w = <. x , y >. /\ z = R ) ) ) | 
						
							| 29 | 28 | 2exbii |  |-  ( E. x E. y ( w = <. x , y >. /\ ( <. x , y >. e. C /\ z = R ) ) <-> E. x E. y ( w e. C /\ ( w = <. x , y >. /\ z = R ) ) ) | 
						
							| 30 |  | 19.42vv |  |-  ( E. x E. y ( w e. C /\ ( w = <. x , y >. /\ z = R ) ) <-> ( w e. C /\ E. x E. y ( w = <. x , y >. /\ z = R ) ) ) | 
						
							| 31 | 29 30 | bitri |  |-  ( E. x E. y ( w = <. x , y >. /\ ( <. x , y >. e. C /\ z = R ) ) <-> ( w e. C /\ E. x E. y ( w = <. x , y >. /\ z = R ) ) ) | 
						
							| 32 | 31 | opabbii |  |-  { <. w , z >. | E. x E. y ( w = <. x , y >. /\ ( <. x , y >. e. C /\ z = R ) ) } = { <. w , z >. | ( w e. C /\ E. x E. y ( w = <. x , y >. /\ z = R ) ) } | 
						
							| 33 | 2 23 32 | 3eqtri |  |-  F = { <. w , z >. | ( w e. C /\ E. x E. y ( w = <. x , y >. /\ z = R ) ) } | 
						
							| 34 | 16 19 22 33 | fvopab3ig |  |-  ( ( <. A , B >. e. C /\ S e. J ) -> ( E. x E. y ( <. A , B >. = <. x , y >. /\ S = S ) -> ( F ` <. A , B >. ) = S ) ) | 
						
							| 35 | 34 | 3ad2antl3 |  |-  ( ( ( A e. G /\ B e. H /\ <. A , B >. e. C ) /\ S e. J ) -> ( E. x E. y ( <. A , B >. = <. x , y >. /\ S = S ) -> ( F ` <. A , B >. ) = S ) ) | 
						
							| 36 | 9 35 | mpd |  |-  ( ( ( A e. G /\ B e. H /\ <. A , B >. e. C ) /\ S e. J ) -> ( F ` <. A , B >. ) = S ) | 
						
							| 37 | 3 36 | eqtrid |  |-  ( ( ( A e. G /\ B e. H /\ <. A , B >. e. C ) /\ S e. J ) -> ( A F B ) = S ) |