| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isthincd2lem1.1 |  |-  ( ph -> X e. B ) | 
						
							| 2 |  | isthincd2lem1.2 |  |-  ( ph -> Y e. B ) | 
						
							| 3 |  | isthincd2lem1.3 |  |-  ( ph -> F e. ( X H Y ) ) | 
						
							| 4 |  | isthincd2lem1.4 |  |-  ( ph -> G e. ( X H Y ) ) | 
						
							| 5 |  | isthincd2lem1.5 |  |-  ( ph -> A. x e. B A. y e. B E* f f e. ( x H y ) ) | 
						
							| 6 |  | oveq1 |  |-  ( x = z -> ( x H y ) = ( z H y ) ) | 
						
							| 7 | 6 | eleq2d |  |-  ( x = z -> ( f e. ( x H y ) <-> f e. ( z H y ) ) ) | 
						
							| 8 | 7 | mobidv |  |-  ( x = z -> ( E* f f e. ( x H y ) <-> E* f f e. ( z H y ) ) ) | 
						
							| 9 |  | oveq2 |  |-  ( y = w -> ( z H y ) = ( z H w ) ) | 
						
							| 10 | 9 | eleq2d |  |-  ( y = w -> ( f e. ( z H y ) <-> f e. ( z H w ) ) ) | 
						
							| 11 | 10 | mobidv |  |-  ( y = w -> ( E* f f e. ( z H y ) <-> E* f f e. ( z H w ) ) ) | 
						
							| 12 | 8 11 | cbvral2vw |  |-  ( A. x e. B A. y e. B E* f f e. ( x H y ) <-> A. z e. B A. w e. B E* f f e. ( z H w ) ) | 
						
							| 13 | 5 12 | sylib |  |-  ( ph -> A. z e. B A. w e. B E* f f e. ( z H w ) ) | 
						
							| 14 |  | oveq1 |  |-  ( z = X -> ( z H w ) = ( X H w ) ) | 
						
							| 15 | 14 | eleq2d |  |-  ( z = X -> ( f e. ( z H w ) <-> f e. ( X H w ) ) ) | 
						
							| 16 | 15 | mobidv |  |-  ( z = X -> ( E* f f e. ( z H w ) <-> E* f f e. ( X H w ) ) ) | 
						
							| 17 |  | nfv |  |-  F/ k f e. ( X H w ) | 
						
							| 18 |  | nfv |  |-  F/ f k e. ( X H w ) | 
						
							| 19 |  | eleq1w |  |-  ( f = k -> ( f e. ( X H w ) <-> k e. ( X H w ) ) ) | 
						
							| 20 | 17 18 19 | cbvmow |  |-  ( E* f f e. ( X H w ) <-> E* k k e. ( X H w ) ) | 
						
							| 21 |  | oveq2 |  |-  ( w = Y -> ( X H w ) = ( X H Y ) ) | 
						
							| 22 | 21 | eleq2d |  |-  ( w = Y -> ( k e. ( X H w ) <-> k e. ( X H Y ) ) ) | 
						
							| 23 | 22 | mobidv |  |-  ( w = Y -> ( E* k k e. ( X H w ) <-> E* k k e. ( X H Y ) ) ) | 
						
							| 24 | 20 23 | bitrid |  |-  ( w = Y -> ( E* f f e. ( X H w ) <-> E* k k e. ( X H Y ) ) ) | 
						
							| 25 |  | eqidd |  |-  ( ( ph /\ z = X ) -> B = B ) | 
						
							| 26 | 16 24 1 25 2 | rspc2vd |  |-  ( ph -> ( A. z e. B A. w e. B E* f f e. ( z H w ) -> E* k k e. ( X H Y ) ) ) | 
						
							| 27 | 13 26 | mpd |  |-  ( ph -> E* k k e. ( X H Y ) ) | 
						
							| 28 |  | moel |  |-  ( E* k k e. ( X H Y ) <-> A. k e. ( X H Y ) A. l e. ( X H Y ) k = l ) | 
						
							| 29 | 27 28 | sylib |  |-  ( ph -> A. k e. ( X H Y ) A. l e. ( X H Y ) k = l ) | 
						
							| 30 |  | eqeq1 |  |-  ( k = F -> ( k = l <-> F = l ) ) | 
						
							| 31 |  | eqeq2 |  |-  ( l = G -> ( F = l <-> F = G ) ) | 
						
							| 32 |  | eqidd |  |-  ( ( ph /\ k = F ) -> ( X H Y ) = ( X H Y ) ) | 
						
							| 33 | 30 31 3 32 4 | rspc2vd |  |-  ( ph -> ( A. k e. ( X H Y ) A. l e. ( X H Y ) k = l -> F = G ) ) | 
						
							| 34 | 29 33 | mpd |  |-  ( ph -> F = G ) |