| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pgindnf.1 |  |-  F/ x ph | 
						
							| 2 |  | pgindnf.2 |  |-  F/ y ph | 
						
							| 3 |  | pgindnf.3 |  |-  ( x = y -> ( ps <-> ch ) ) | 
						
							| 4 |  | pgindnf.4 |  |-  ( y = A -> ( ch <-> th ) ) | 
						
							| 5 |  | pgindnf.5 |  |-  ( ph -> A. x ( A. y e. ( ( 1st ` x ) u. ( 2nd ` x ) ) ch -> ps ) ) | 
						
							| 6 |  | df-pg |  |-  Pg = setrecs ( ( a e. _V |-> ( ~P a X. ~P a ) ) ) | 
						
							| 7 |  | nfv |  |-  F/ x A. y e. z ch | 
						
							| 8 | 1 7 | nfan |  |-  F/ x ( ph /\ A. y e. z ch ) | 
						
							| 9 |  | pgindlem |  |-  ( x e. ( ~P z X. ~P z ) -> ( ( 1st ` x ) u. ( 2nd ` x ) ) C_ z ) | 
						
							| 10 | 9 | sseld |  |-  ( x e. ( ~P z X. ~P z ) -> ( y e. ( ( 1st ` x ) u. ( 2nd ` x ) ) -> y e. z ) ) | 
						
							| 11 | 10 | imim1d |  |-  ( x e. ( ~P z X. ~P z ) -> ( ( y e. z -> ch ) -> ( y e. ( ( 1st ` x ) u. ( 2nd ` x ) ) -> ch ) ) ) | 
						
							| 12 | 11 | ralimdv2 |  |-  ( x e. ( ~P z X. ~P z ) -> ( A. y e. z ch -> A. y e. ( ( 1st ` x ) u. ( 2nd ` x ) ) ch ) ) | 
						
							| 13 | 5 | 19.21bi |  |-  ( ph -> ( A. y e. ( ( 1st ` x ) u. ( 2nd ` x ) ) ch -> ps ) ) | 
						
							| 14 | 12 13 | sylan9r |  |-  ( ( ph /\ x e. ( ~P z X. ~P z ) ) -> ( A. y e. z ch -> ps ) ) | 
						
							| 15 | 14 | impancom |  |-  ( ( ph /\ A. y e. z ch ) -> ( x e. ( ~P z X. ~P z ) -> ps ) ) | 
						
							| 16 | 8 15 | ralrimi |  |-  ( ( ph /\ A. y e. z ch ) -> A. x e. ( ~P z X. ~P z ) ps ) | 
						
							| 17 |  | vex |  |-  z e. _V | 
						
							| 18 |  | pweq |  |-  ( a = z -> ~P a = ~P z ) | 
						
							| 19 | 18 | sqxpeqd |  |-  ( a = z -> ( ~P a X. ~P a ) = ( ~P z X. ~P z ) ) | 
						
							| 20 |  | eqid |  |-  ( a e. _V |-> ( ~P a X. ~P a ) ) = ( a e. _V |-> ( ~P a X. ~P a ) ) | 
						
							| 21 |  | vpwex |  |-  ~P z e. _V | 
						
							| 22 | 21 21 | xpex |  |-  ( ~P z X. ~P z ) e. _V | 
						
							| 23 | 19 20 22 | fvmpt |  |-  ( z e. _V -> ( ( a e. _V |-> ( ~P a X. ~P a ) ) ` z ) = ( ~P z X. ~P z ) ) | 
						
							| 24 | 17 23 | ax-mp |  |-  ( ( a e. _V |-> ( ~P a X. ~P a ) ) ` z ) = ( ~P z X. ~P z ) | 
						
							| 25 | 24 | eqcomi |  |-  ( ~P z X. ~P z ) = ( ( a e. _V |-> ( ~P a X. ~P a ) ) ` z ) | 
						
							| 26 | 25 | a1i |  |-  ( x = y -> ( ~P z X. ~P z ) = ( ( a e. _V |-> ( ~P a X. ~P a ) ) ` z ) ) | 
						
							| 27 | 3 26 | cbvralv2 |  |-  ( A. x e. ( ~P z X. ~P z ) ps <-> A. y e. ( ( a e. _V |-> ( ~P a X. ~P a ) ) ` z ) ch ) | 
						
							| 28 | 16 27 | sylib |  |-  ( ( ph /\ A. y e. z ch ) -> A. y e. ( ( a e. _V |-> ( ~P a X. ~P a ) ) ` z ) ch ) | 
						
							| 29 | 28 | ex |  |-  ( ph -> ( A. y e. z ch -> A. y e. ( ( a e. _V |-> ( ~P a X. ~P a ) ) ` z ) ch ) ) | 
						
							| 30 | 29 | alrimiv |  |-  ( ph -> A. z ( A. y e. z ch -> A. y e. ( ( a e. _V |-> ( ~P a X. ~P a ) ) ` z ) ch ) ) | 
						
							| 31 | 6 4 30 | setis |  |-  ( ph -> ( A e. Pg -> th ) ) |