| Step | Hyp | Ref | Expression | 
						
							| 1 |  | unirep.1 |  |-  ( y = D -> ( ph <-> ps ) ) | 
						
							| 2 |  | unirep.2 |  |-  ( y = D -> B = C ) | 
						
							| 3 |  | unirep.3 |  |-  ( y = z -> ( ph <-> ch ) ) | 
						
							| 4 |  | unirep.4 |  |-  ( y = z -> B = F ) | 
						
							| 5 |  | unirep.5 |  |-  B e. _V | 
						
							| 6 |  | eqidd |  |-  ( ps -> C = C ) | 
						
							| 7 | 6 | ancli |  |-  ( ps -> ( ps /\ C = C ) ) | 
						
							| 8 | 2 | eqeq2d |  |-  ( y = D -> ( C = B <-> C = C ) ) | 
						
							| 9 | 1 8 | anbi12d |  |-  ( y = D -> ( ( ph /\ C = B ) <-> ( ps /\ C = C ) ) ) | 
						
							| 10 | 9 | rspcev |  |-  ( ( D e. A /\ ( ps /\ C = C ) ) -> E. y e. A ( ph /\ C = B ) ) | 
						
							| 11 | 7 10 | sylan2 |  |-  ( ( D e. A /\ ps ) -> E. y e. A ( ph /\ C = B ) ) | 
						
							| 12 | 11 | adantl |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( D e. A /\ ps ) ) -> E. y e. A ( ph /\ C = B ) ) | 
						
							| 13 |  | nfcvd |  |-  ( D e. A -> F/_ y C ) | 
						
							| 14 | 13 2 | csbiegf |  |-  ( D e. A -> [_ D / y ]_ B = C ) | 
						
							| 15 | 5 | csbex |  |-  [_ D / y ]_ B e. _V | 
						
							| 16 | 14 15 | eqeltrrdi |  |-  ( D e. A -> C e. _V ) | 
						
							| 17 | 16 | ad2antrl |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( D e. A /\ ps ) ) -> C e. _V ) | 
						
							| 18 |  | eqeq1 |  |-  ( x = C -> ( x = B <-> C = B ) ) | 
						
							| 19 | 18 | anbi2d |  |-  ( x = C -> ( ( ph /\ x = B ) <-> ( ph /\ C = B ) ) ) | 
						
							| 20 | 19 | rexbidv |  |-  ( x = C -> ( E. y e. A ( ph /\ x = B ) <-> E. y e. A ( ph /\ C = B ) ) ) | 
						
							| 21 | 20 | spcegv |  |-  ( C e. _V -> ( E. y e. A ( ph /\ C = B ) -> E. x E. y e. A ( ph /\ x = B ) ) ) | 
						
							| 22 | 16 21 | syl |  |-  ( D e. A -> ( E. y e. A ( ph /\ C = B ) -> E. x E. y e. A ( ph /\ x = B ) ) ) | 
						
							| 23 | 22 | adantr |  |-  ( ( D e. A /\ ps ) -> ( E. y e. A ( ph /\ C = B ) -> E. x E. y e. A ( ph /\ x = B ) ) ) | 
						
							| 24 | 11 23 | mpd |  |-  ( ( D e. A /\ ps ) -> E. x E. y e. A ( ph /\ x = B ) ) | 
						
							| 25 | 24 | adantl |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( D e. A /\ ps ) ) -> E. x E. y e. A ( ph /\ x = B ) ) | 
						
							| 26 |  | r19.29 |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ E. y e. A ( ph /\ x = B ) ) -> E. y e. A ( A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( ph /\ x = B ) ) ) | 
						
							| 27 |  | r19.29 |  |-  ( ( A. z e. A ( ( ph /\ ch ) -> B = F ) /\ E. z e. A ( ch /\ w = F ) ) -> E. z e. A ( ( ( ph /\ ch ) -> B = F ) /\ ( ch /\ w = F ) ) ) | 
						
							| 28 |  | an4 |  |-  ( ( ( ph /\ x = B ) /\ ( ch /\ w = F ) ) <-> ( ( ph /\ ch ) /\ ( x = B /\ w = F ) ) ) | 
						
							| 29 |  | pm3.35 |  |-  ( ( ( ph /\ ch ) /\ ( ( ph /\ ch ) -> B = F ) ) -> B = F ) | 
						
							| 30 |  | eqeq12 |  |-  ( ( x = B /\ w = F ) -> ( x = w <-> B = F ) ) | 
						
							| 31 | 29 30 | syl5ibrcom |  |-  ( ( ( ph /\ ch ) /\ ( ( ph /\ ch ) -> B = F ) ) -> ( ( x = B /\ w = F ) -> x = w ) ) | 
						
							| 32 | 31 | ancoms |  |-  ( ( ( ( ph /\ ch ) -> B = F ) /\ ( ph /\ ch ) ) -> ( ( x = B /\ w = F ) -> x = w ) ) | 
						
							| 33 | 32 | expimpd |  |-  ( ( ( ph /\ ch ) -> B = F ) -> ( ( ( ph /\ ch ) /\ ( x = B /\ w = F ) ) -> x = w ) ) | 
						
							| 34 | 28 33 | biimtrid |  |-  ( ( ( ph /\ ch ) -> B = F ) -> ( ( ( ph /\ x = B ) /\ ( ch /\ w = F ) ) -> x = w ) ) | 
						
							| 35 | 34 | ancomsd |  |-  ( ( ( ph /\ ch ) -> B = F ) -> ( ( ( ch /\ w = F ) /\ ( ph /\ x = B ) ) -> x = w ) ) | 
						
							| 36 | 35 | expdimp |  |-  ( ( ( ( ph /\ ch ) -> B = F ) /\ ( ch /\ w = F ) ) -> ( ( ph /\ x = B ) -> x = w ) ) | 
						
							| 37 | 36 | rexlimivw |  |-  ( E. z e. A ( ( ( ph /\ ch ) -> B = F ) /\ ( ch /\ w = F ) ) -> ( ( ph /\ x = B ) -> x = w ) ) | 
						
							| 38 | 37 | imp |  |-  ( ( E. z e. A ( ( ( ph /\ ch ) -> B = F ) /\ ( ch /\ w = F ) ) /\ ( ph /\ x = B ) ) -> x = w ) | 
						
							| 39 | 27 38 | sylan |  |-  ( ( ( A. z e. A ( ( ph /\ ch ) -> B = F ) /\ E. z e. A ( ch /\ w = F ) ) /\ ( ph /\ x = B ) ) -> x = w ) | 
						
							| 40 | 39 | an32s |  |-  ( ( ( A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( ph /\ x = B ) ) /\ E. z e. A ( ch /\ w = F ) ) -> x = w ) | 
						
							| 41 | 40 | ex |  |-  ( ( A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( ph /\ x = B ) ) -> ( E. z e. A ( ch /\ w = F ) -> x = w ) ) | 
						
							| 42 | 41 | rexlimivw |  |-  ( E. y e. A ( A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( ph /\ x = B ) ) -> ( E. z e. A ( ch /\ w = F ) -> x = w ) ) | 
						
							| 43 | 26 42 | syl |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ E. y e. A ( ph /\ x = B ) ) -> ( E. z e. A ( ch /\ w = F ) -> x = w ) ) | 
						
							| 44 | 43 | expimpd |  |-  ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) -> ( ( E. y e. A ( ph /\ x = B ) /\ E. z e. A ( ch /\ w = F ) ) -> x = w ) ) | 
						
							| 45 | 44 | adantr |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( D e. A /\ ps ) ) -> ( ( E. y e. A ( ph /\ x = B ) /\ E. z e. A ( ch /\ w = F ) ) -> x = w ) ) | 
						
							| 46 | 45 | alrimivv |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( D e. A /\ ps ) ) -> A. x A. w ( ( E. y e. A ( ph /\ x = B ) /\ E. z e. A ( ch /\ w = F ) ) -> x = w ) ) | 
						
							| 47 |  | eqeq1 |  |-  ( x = w -> ( x = B <-> w = B ) ) | 
						
							| 48 | 47 | anbi2d |  |-  ( x = w -> ( ( ph /\ x = B ) <-> ( ph /\ w = B ) ) ) | 
						
							| 49 | 48 | rexbidv |  |-  ( x = w -> ( E. y e. A ( ph /\ x = B ) <-> E. y e. A ( ph /\ w = B ) ) ) | 
						
							| 50 | 4 | eqeq2d |  |-  ( y = z -> ( w = B <-> w = F ) ) | 
						
							| 51 | 3 50 | anbi12d |  |-  ( y = z -> ( ( ph /\ w = B ) <-> ( ch /\ w = F ) ) ) | 
						
							| 52 | 51 | cbvrexvw |  |-  ( E. y e. A ( ph /\ w = B ) <-> E. z e. A ( ch /\ w = F ) ) | 
						
							| 53 | 49 52 | bitrdi |  |-  ( x = w -> ( E. y e. A ( ph /\ x = B ) <-> E. z e. A ( ch /\ w = F ) ) ) | 
						
							| 54 | 53 | eu4 |  |-  ( E! x E. y e. A ( ph /\ x = B ) <-> ( E. x E. y e. A ( ph /\ x = B ) /\ A. x A. w ( ( E. y e. A ( ph /\ x = B ) /\ E. z e. A ( ch /\ w = F ) ) -> x = w ) ) ) | 
						
							| 55 | 25 46 54 | sylanbrc |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( D e. A /\ ps ) ) -> E! x E. y e. A ( ph /\ x = B ) ) | 
						
							| 56 | 20 | iota2 |  |-  ( ( C e. _V /\ E! x E. y e. A ( ph /\ x = B ) ) -> ( E. y e. A ( ph /\ C = B ) <-> ( iota x E. y e. A ( ph /\ x = B ) ) = C ) ) | 
						
							| 57 | 17 55 56 | syl2anc |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( D e. A /\ ps ) ) -> ( E. y e. A ( ph /\ C = B ) <-> ( iota x E. y e. A ( ph /\ x = B ) ) = C ) ) | 
						
							| 58 | 12 57 | mpbid |  |-  ( ( A. y e. A A. z e. A ( ( ph /\ ch ) -> B = F ) /\ ( D e. A /\ ps ) ) -> ( iota x E. y e. A ( ph /\ x = B ) ) = C ) |