| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cbvrabcsfw.1 |  |-  F/_ y A | 
						
							| 2 |  | cbvrabcsfw.2 |  |-  F/_ x B | 
						
							| 3 |  | cbvrabcsfw.3 |  |-  F/ y ph | 
						
							| 4 |  | cbvrabcsfw.4 |  |-  F/ x ps | 
						
							| 5 |  | cbvrabcsfw.5 |  |-  ( x = y -> A = B ) | 
						
							| 6 |  | cbvrabcsfw.6 |  |-  ( x = y -> ( ph <-> ps ) ) | 
						
							| 7 |  | nfv |  |-  F/ z ( x e. A /\ ph ) | 
						
							| 8 |  | nfcsb1v |  |-  F/_ x [_ z / x ]_ A | 
						
							| 9 | 8 | nfcri |  |-  F/ x z e. [_ z / x ]_ A | 
						
							| 10 |  | nfs1v |  |-  F/ x [ z / x ] ph | 
						
							| 11 | 9 10 | nfan |  |-  F/ x ( z e. [_ z / x ]_ A /\ [ z / x ] ph ) | 
						
							| 12 |  | id |  |-  ( x = z -> x = z ) | 
						
							| 13 |  | csbeq1a |  |-  ( x = z -> A = [_ z / x ]_ A ) | 
						
							| 14 | 12 13 | eleq12d |  |-  ( x = z -> ( x e. A <-> z e. [_ z / x ]_ A ) ) | 
						
							| 15 |  | sbequ12 |  |-  ( x = z -> ( ph <-> [ z / x ] ph ) ) | 
						
							| 16 | 14 15 | anbi12d |  |-  ( x = z -> ( ( x e. A /\ ph ) <-> ( z e. [_ z / x ]_ A /\ [ z / x ] ph ) ) ) | 
						
							| 17 | 7 11 16 | cbvabw |  |-  { x | ( x e. A /\ ph ) } = { z | ( z e. [_ z / x ]_ A /\ [ z / x ] ph ) } | 
						
							| 18 |  | nfcv |  |-  F/_ y z | 
						
							| 19 | 18 1 | nfcsbw |  |-  F/_ y [_ z / x ]_ A | 
						
							| 20 | 19 | nfcri |  |-  F/ y z e. [_ z / x ]_ A | 
						
							| 21 | 3 | nfsbv |  |-  F/ y [ z / x ] ph | 
						
							| 22 | 20 21 | nfan |  |-  F/ y ( z e. [_ z / x ]_ A /\ [ z / x ] ph ) | 
						
							| 23 |  | nfv |  |-  F/ z ( y e. B /\ ps ) | 
						
							| 24 |  | id |  |-  ( z = y -> z = y ) | 
						
							| 25 |  | csbeq1 |  |-  ( z = y -> [_ z / x ]_ A = [_ y / x ]_ A ) | 
						
							| 26 |  | vex |  |-  y e. _V | 
						
							| 27 | 26 2 5 | csbief |  |-  [_ y / x ]_ A = B | 
						
							| 28 | 25 27 | eqtrdi |  |-  ( z = y -> [_ z / x ]_ A = B ) | 
						
							| 29 | 24 28 | eleq12d |  |-  ( z = y -> ( z e. [_ z / x ]_ A <-> y e. B ) ) | 
						
							| 30 | 4 6 | sbhypf |  |-  ( z = y -> ( [ z / x ] ph <-> ps ) ) | 
						
							| 31 | 29 30 | anbi12d |  |-  ( z = y -> ( ( z e. [_ z / x ]_ A /\ [ z / x ] ph ) <-> ( y e. B /\ ps ) ) ) | 
						
							| 32 | 22 23 31 | cbvabw |  |-  { z | ( z e. [_ z / x ]_ A /\ [ z / x ] ph ) } = { y | ( y e. B /\ ps ) } | 
						
							| 33 | 17 32 | eqtri |  |-  { x | ( x e. A /\ ph ) } = { y | ( y e. B /\ ps ) } | 
						
							| 34 |  | df-rab |  |-  { x e. A | ph } = { x | ( x e. A /\ ph ) } | 
						
							| 35 |  | df-rab |  |-  { y e. B | ps } = { y | ( y e. B /\ ps ) } | 
						
							| 36 | 33 34 35 | 3eqtr4i |  |-  { x e. A | ph } = { y e. B | ps } |