| Step | Hyp | Ref | Expression | 
						
							| 1 |  | scottabf.1 |  |-  F/ x ps | 
						
							| 2 |  | scottabf.2 |  |-  ( x = y -> ( ph <-> ps ) ) | 
						
							| 3 |  | df-scott |  |-  Scott { x | ph } = { z e. { x | ph } | A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) } | 
						
							| 4 |  | df-rab |  |-  { z e. { x | ph } | A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) } = { z | ( z e. { x | ph } /\ A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) ) } | 
						
							| 5 |  | eqabcb |  |-  ( { z | ( z e. { x | ph } /\ A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) ) } = { x | ( ph /\ A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) ) } <-> A. z ( ( z e. { x | ph } /\ A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) ) <-> z e. { x | ( ph /\ A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) ) } ) ) | 
						
							| 6 |  | nfsab1 |  |-  F/ x z e. { x | ph } | 
						
							| 7 |  | nfab1 |  |-  F/_ x { x | ph } | 
						
							| 8 |  | nfv |  |-  F/ x ( rank ` z ) C_ ( rank ` w ) | 
						
							| 9 | 7 8 | nfralw |  |-  F/ x A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) | 
						
							| 10 | 6 9 | nfan |  |-  F/ x ( z e. { x | ph } /\ A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) ) | 
						
							| 11 |  | vex |  |-  z e. _V | 
						
							| 12 |  | abid |  |-  ( x e. { x | ph } <-> ph ) | 
						
							| 13 |  | eleq1w |  |-  ( x = z -> ( x e. { x | ph } <-> z e. { x | ph } ) ) | 
						
							| 14 | 12 13 | bitr3id |  |-  ( x = z -> ( ph <-> z e. { x | ph } ) ) | 
						
							| 15 |  | df-clab |  |-  ( y e. { x | ph } <-> [ y / x ] ph ) | 
						
							| 16 | 1 2 | sbiev |  |-  ( [ y / x ] ph <-> ps ) | 
						
							| 17 | 15 16 | bitr2i |  |-  ( ps <-> y e. { x | ph } ) | 
						
							| 18 |  | eleq1w |  |-  ( y = w -> ( y e. { x | ph } <-> w e. { x | ph } ) ) | 
						
							| 19 | 17 18 | bitrid |  |-  ( y = w -> ( ps <-> w e. { x | ph } ) ) | 
						
							| 20 | 19 | adantl |  |-  ( ( x = z /\ y = w ) -> ( ps <-> w e. { x | ph } ) ) | 
						
							| 21 |  | simpl |  |-  ( ( x = z /\ y = w ) -> x = z ) | 
						
							| 22 | 21 | fveq2d |  |-  ( ( x = z /\ y = w ) -> ( rank ` x ) = ( rank ` z ) ) | 
						
							| 23 |  | simpr |  |-  ( ( x = z /\ y = w ) -> y = w ) | 
						
							| 24 | 23 | fveq2d |  |-  ( ( x = z /\ y = w ) -> ( rank ` y ) = ( rank ` w ) ) | 
						
							| 25 | 22 24 | sseq12d |  |-  ( ( x = z /\ y = w ) -> ( ( rank ` x ) C_ ( rank ` y ) <-> ( rank ` z ) C_ ( rank ` w ) ) ) | 
						
							| 26 | 20 25 | imbi12d |  |-  ( ( x = z /\ y = w ) -> ( ( ps -> ( rank ` x ) C_ ( rank ` y ) ) <-> ( w e. { x | ph } -> ( rank ` z ) C_ ( rank ` w ) ) ) ) | 
						
							| 27 | 26 | cbvaldvaw |  |-  ( x = z -> ( A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) <-> A. w ( w e. { x | ph } -> ( rank ` z ) C_ ( rank ` w ) ) ) ) | 
						
							| 28 |  | df-ral |  |-  ( A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) <-> A. w ( w e. { x | ph } -> ( rank ` z ) C_ ( rank ` w ) ) ) | 
						
							| 29 | 27 28 | bitr4di |  |-  ( x = z -> ( A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) <-> A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) ) ) | 
						
							| 30 | 14 29 | anbi12d |  |-  ( x = z -> ( ( ph /\ A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) ) <-> ( z e. { x | ph } /\ A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) ) ) ) | 
						
							| 31 | 10 11 30 | elabf |  |-  ( z e. { x | ( ph /\ A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) ) } <-> ( z e. { x | ph } /\ A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) ) ) | 
						
							| 32 | 31 | bicomi |  |-  ( ( z e. { x | ph } /\ A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) ) <-> z e. { x | ( ph /\ A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) ) } ) | 
						
							| 33 | 5 32 | mpgbir |  |-  { z | ( z e. { x | ph } /\ A. w e. { x | ph } ( rank ` z ) C_ ( rank ` w ) ) } = { x | ( ph /\ A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) ) } | 
						
							| 34 | 3 4 33 | 3eqtri |  |-  Scott { x | ph } = { x | ( ph /\ A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) ) } |