| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj580.1 | 
							 |-  ( ph <-> ( f ` (/) ) = _pred ( x , A , R ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj580.2 | 
							 |-  ( ps <-> A. i e. _om ( suc i e. n -> ( f ` suc i ) = U_ y e. ( f ` i ) _pred ( y , A , R ) ) )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj580.3 | 
							 |-  ( ch <-> ( f Fn n /\ ph /\ ps ) )  | 
						
						
							| 4 | 
							
								
							 | 
							bnj580.4 | 
							 |-  ( ph' <-> [. g / f ]. ph )  | 
						
						
							| 5 | 
							
								
							 | 
							bnj580.5 | 
							 |-  ( ps' <-> [. g / f ]. ps )  | 
						
						
							| 6 | 
							
								
							 | 
							bnj580.6 | 
							 |-  ( ch' <-> [. g / f ]. ch )  | 
						
						
							| 7 | 
							
								
							 | 
							bnj580.7 | 
							 |-  D = ( _om \ { (/) } ) | 
						
						
							| 8 | 
							
								
							 | 
							bnj580.8 | 
							 |-  ( th <-> ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) )  | 
						
						
							| 9 | 
							
								
							 | 
							bnj580.9 | 
							 |-  ( ta <-> A. k e. n ( k _E j -> [. k / j ]. th ) )  | 
						
						
							| 10 | 
							
								3
							 | 
							simp1bi | 
							 |-  ( ch -> f Fn n )  | 
						
						
							| 11 | 
							
								3 4 5 6
							 | 
							bnj581 | 
							 |-  ( ch' <-> ( g Fn n /\ ph' /\ ps' ) )  | 
						
						
							| 12 | 
							
								11
							 | 
							simp1bi | 
							 |-  ( ch' -> g Fn n )  | 
						
						
							| 13 | 
							
								10 12
							 | 
							bnj240 | 
							 |-  ( ( n e. D /\ ch /\ ch' ) -> ( f Fn n /\ g Fn n ) )  | 
						
						
							| 14 | 
							
								4 1
							 | 
							bnj154 | 
							 |-  ( ph' <-> ( g ` (/) ) = _pred ( x , A , R ) )  | 
						
						
							| 15 | 
							
								
							 | 
							vex | 
							 |-  g e. _V  | 
						
						
							| 16 | 
							
								2 5 15
							 | 
							bnj540 | 
							 |-  ( ps' <-> A. i e. _om ( suc i e. n -> ( g ` suc i ) = U_ y e. ( g ` i ) _pred ( y , A , R ) ) )  | 
						
						
							| 17 | 
							
								8
							 | 
							bnj591 | 
							 |-  ( [. k / j ]. th <-> ( ( n e. D /\ ch /\ ch' ) -> ( f ` k ) = ( g ` k ) ) )  | 
						
						
							| 18 | 
							
								1 2 3 7 14 16 11 8 17 9
							 | 
							bnj594 | 
							 |-  ( ( j e. n /\ ta ) -> th )  | 
						
						
							| 19 | 
							
								18
							 | 
							ex | 
							 |-  ( j e. n -> ( ta -> th ) )  | 
						
						
							| 20 | 
							
								19
							 | 
							rgen | 
							 |-  A. j e. n ( ta -> th )  | 
						
						
							| 21 | 
							
								
							 | 
							vex | 
							 |-  n e. _V  | 
						
						
							| 22 | 
							
								21 9
							 | 
							bnj110 | 
							 |-  ( ( _E Fr n /\ A. j e. n ( ta -> th ) ) -> A. j e. n th )  | 
						
						
							| 23 | 
							
								20 22
							 | 
							mpan2 | 
							 |-  ( _E Fr n -> A. j e. n th )  | 
						
						
							| 24 | 
							
								8
							 | 
							ralbii | 
							 |-  ( A. j e. n th <-> A. j e. n ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) )  | 
						
						
							| 25 | 
							
								23 24
							 | 
							sylib | 
							 |-  ( _E Fr n -> A. j e. n ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) )  | 
						
						
							| 26 | 
							
								25
							 | 
							r19.21be | 
							 |-  A. j e. n ( _E Fr n -> ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) )  | 
						
						
							| 27 | 
							
								7
							 | 
							bnj923 | 
							 |-  ( n e. D -> n e. _om )  | 
						
						
							| 28 | 
							
								
							 | 
							nnord | 
							 |-  ( n e. _om -> Ord n )  | 
						
						
							| 29 | 
							
								
							 | 
							ordfr | 
							 |-  ( Ord n -> _E Fr n )  | 
						
						
							| 30 | 
							
								27 28 29
							 | 
							3syl | 
							 |-  ( n e. D -> _E Fr n )  | 
						
						
							| 31 | 
							
								30
							 | 
							3ad2ant1 | 
							 |-  ( ( n e. D /\ ch /\ ch' ) -> _E Fr n )  | 
						
						
							| 32 | 
							
								31
							 | 
							pm4.71ri | 
							 |-  ( ( n e. D /\ ch /\ ch' ) <-> ( _E Fr n /\ ( n e. D /\ ch /\ ch' ) ) )  | 
						
						
							| 33 | 
							
								32
							 | 
							imbi1i | 
							 |-  ( ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) <-> ( ( _E Fr n /\ ( n e. D /\ ch /\ ch' ) ) -> ( f ` j ) = ( g ` j ) ) )  | 
						
						
							| 34 | 
							
								
							 | 
							impexp | 
							 |-  ( ( ( _E Fr n /\ ( n e. D /\ ch /\ ch' ) ) -> ( f ` j ) = ( g ` j ) ) <-> ( _E Fr n -> ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) ) )  | 
						
						
							| 35 | 
							
								33 34
							 | 
							bitri | 
							 |-  ( ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) <-> ( _E Fr n -> ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) ) )  | 
						
						
							| 36 | 
							
								35
							 | 
							ralbii | 
							 |-  ( A. j e. n ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) <-> A. j e. n ( _E Fr n -> ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) ) )  | 
						
						
							| 37 | 
							
								26 36
							 | 
							mpbir | 
							 |-  A. j e. n ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) )  | 
						
						
							| 38 | 
							
								
							 | 
							r19.21v | 
							 |-  ( A. j e. n ( ( n e. D /\ ch /\ ch' ) -> ( f ` j ) = ( g ` j ) ) <-> ( ( n e. D /\ ch /\ ch' ) -> A. j e. n ( f ` j ) = ( g ` j ) ) )  | 
						
						
							| 39 | 
							
								37 38
							 | 
							mpbi | 
							 |-  ( ( n e. D /\ ch /\ ch' ) -> A. j e. n ( f ` j ) = ( g ` j ) )  | 
						
						
							| 40 | 
							
								
							 | 
							eqfnfv | 
							 |-  ( ( f Fn n /\ g Fn n ) -> ( f = g <-> A. j e. n ( f ` j ) = ( g ` j ) ) )  | 
						
						
							| 41 | 
							
								40
							 | 
							biimprd | 
							 |-  ( ( f Fn n /\ g Fn n ) -> ( A. j e. n ( f ` j ) = ( g ` j ) -> f = g ) )  | 
						
						
							| 42 | 
							
								13 39 41
							 | 
							sylc | 
							 |-  ( ( n e. D /\ ch /\ ch' ) -> f = g )  | 
						
						
							| 43 | 
							
								42
							 | 
							3expib | 
							 |-  ( n e. D -> ( ( ch /\ ch' ) -> f = g ) )  | 
						
						
							| 44 | 
							
								43
							 | 
							alrimivv | 
							 |-  ( n e. D -> A. f A. g ( ( ch /\ ch' ) -> f = g ) )  | 
						
						
							| 45 | 
							
								
							 | 
							sbsbc | 
							 |-  ( [ g / f ] ch <-> [. g / f ]. ch )  | 
						
						
							| 46 | 
							
								45
							 | 
							anbi2i | 
							 |-  ( ( ch /\ [ g / f ] ch ) <-> ( ch /\ [. g / f ]. ch ) )  | 
						
						
							| 47 | 
							
								46
							 | 
							imbi1i | 
							 |-  ( ( ( ch /\ [ g / f ] ch ) -> f = g ) <-> ( ( ch /\ [. g / f ]. ch ) -> f = g ) )  | 
						
						
							| 48 | 
							
								47
							 | 
							2albii | 
							 |-  ( A. f A. g ( ( ch /\ [ g / f ] ch ) -> f = g ) <-> A. f A. g ( ( ch /\ [. g / f ]. ch ) -> f = g ) )  | 
						
						
							| 49 | 
							
								
							 | 
							nfv | 
							 |-  F/ g ch  | 
						
						
							| 50 | 
							
								49
							 | 
							mo3 | 
							 |-  ( E* f ch <-> A. f A. g ( ( ch /\ [ g / f ] ch ) -> f = g ) )  | 
						
						
							| 51 | 
							
								6
							 | 
							anbi2i | 
							 |-  ( ( ch /\ ch' ) <-> ( ch /\ [. g / f ]. ch ) )  | 
						
						
							| 52 | 
							
								51
							 | 
							imbi1i | 
							 |-  ( ( ( ch /\ ch' ) -> f = g ) <-> ( ( ch /\ [. g / f ]. ch ) -> f = g ) )  | 
						
						
							| 53 | 
							
								52
							 | 
							2albii | 
							 |-  ( A. f A. g ( ( ch /\ ch' ) -> f = g ) <-> A. f A. g ( ( ch /\ [. g / f ]. ch ) -> f = g ) )  | 
						
						
							| 54 | 
							
								48 50 53
							 | 
							3bitr4i | 
							 |-  ( E* f ch <-> A. f A. g ( ( ch /\ ch' ) -> f = g ) )  | 
						
						
							| 55 | 
							
								44 54
							 | 
							sylibr | 
							 |-  ( n e. D -> E* f ch )  |