| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj1128.1 | 
							 |-  ( ph <-> ( f ` (/) ) = _pred ( X , A , R ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj1128.2 | 
							 |-  ( ps <-> A. i e. _om ( suc i e. n -> ( f ` suc i ) = U_ y e. ( f ` i ) _pred ( y , A , R ) ) )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj1128.3 | 
							 |-  D = ( _om \ { (/) } ) | 
						
						
							| 4 | 
							
								
							 | 
							bnj1128.4 | 
							 |-  B = { f | E. n e. D ( f Fn n /\ ph /\ ps ) } | 
						
						
							| 5 | 
							
								
							 | 
							bnj1128.5 | 
							 |-  ( ch <-> ( n e. D /\ f Fn n /\ ph /\ ps ) )  | 
						
						
							| 6 | 
							
								
							 | 
							bnj1128.6 | 
							 |-  ( th <-> ( ch -> ( f ` i ) C_ A ) )  | 
						
						
							| 7 | 
							
								
							 | 
							bnj1128.7 | 
							 |-  ( ta <-> A. j e. n ( j _E i -> [. j / i ]. th ) )  | 
						
						
							| 8 | 
							
								
							 | 
							bnj1128.8 | 
							 |-  ( ph' <-> [. j / i ]. ph )  | 
						
						
							| 9 | 
							
								
							 | 
							bnj1128.9 | 
							 |-  ( ps' <-> [. j / i ]. ps )  | 
						
						
							| 10 | 
							
								
							 | 
							bnj1128.10 | 
							 |-  ( ch' <-> [. j / i ]. ch )  | 
						
						
							| 11 | 
							
								
							 | 
							bnj1128.11 | 
							 |-  ( th' <-> [. j / i ]. th )  | 
						
						
							| 12 | 
							
								1 2 3 4 5
							 | 
							bnj981 | 
							 |-  ( Y e. _trCl ( X , A , R ) -> E. f E. n E. i ( ch /\ i e. n /\ Y e. ( f ` i ) ) )  | 
						
						
							| 13 | 
							
								
							 | 
							simp1 | 
							 |-  ( ( ch /\ i e. n /\ Y e. ( f ` i ) ) -> ch )  | 
						
						
							| 14 | 
							
								
							 | 
							simp2 | 
							 |-  ( ( ch /\ i e. n /\ Y e. ( f ` i ) ) -> i e. n )  | 
						
						
							| 15 | 
							
								
							 | 
							nfv | 
							 |-  F/ j i e. n  | 
						
						
							| 16 | 
							
								
							 | 
							nfra1 | 
							 |-  F/ j A. j e. n ( j _E i -> [. j / i ]. th )  | 
						
						
							| 17 | 
							
								7 16
							 | 
							nfxfr | 
							 |-  F/ j ta  | 
						
						
							| 18 | 
							
								
							 | 
							nfv | 
							 |-  F/ j ch  | 
						
						
							| 19 | 
							
								15 17 18
							 | 
							nf3an | 
							 |-  F/ j ( i e. n /\ ta /\ ch )  | 
						
						
							| 20 | 
							
								
							 | 
							nfv | 
							 |-  F/ j ( f ` i ) C_ A  | 
						
						
							| 21 | 
							
								19 20
							 | 
							nfim | 
							 |-  F/ j ( ( i e. n /\ ta /\ ch ) -> ( f ` i ) C_ A )  | 
						
						
							| 22 | 
							
								21
							 | 
							nf5ri | 
							 |-  ( ( ( i e. n /\ ta /\ ch ) -> ( f ` i ) C_ A ) -> A. j ( ( i e. n /\ ta /\ ch ) -> ( f ` i ) C_ A ) )  | 
						
						
							| 23 | 
							
								3
							 | 
							bnj1098 | 
							 |-  E. j ( ( i =/= (/) /\ i e. n /\ n e. D ) -> ( j e. n /\ i = suc j ) )  | 
						
						
							| 24 | 
							
								
							 | 
							simpl | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> i =/= (/) )  | 
						
						
							| 25 | 
							
								
							 | 
							simpr1 | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> i e. n )  | 
						
						
							| 26 | 
							
								5
							 | 
							bnj1232 | 
							 |-  ( ch -> n e. D )  | 
						
						
							| 27 | 
							
								26
							 | 
							3ad2ant3 | 
							 |-  ( ( i e. n /\ ta /\ ch ) -> n e. D )  | 
						
						
							| 28 | 
							
								27
							 | 
							adantl | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> n e. D )  | 
						
						
							| 29 | 
							
								24 25 28
							 | 
							3jca | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( i =/= (/) /\ i e. n /\ n e. D ) )  | 
						
						
							| 30 | 
							
								23 29
							 | 
							bnj1101 | 
							 |-  E. j ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( j e. n /\ i = suc j ) )  | 
						
						
							| 31 | 
							
								
							 | 
							ancl | 
							 |-  ( ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( j e. n /\ i = suc j ) ) -> ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) /\ ( j e. n /\ i = suc j ) ) ) )  | 
						
						
							| 32 | 
							
								30 31
							 | 
							bnj101 | 
							 |-  E. j ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) /\ ( j e. n /\ i = suc j ) ) )  | 
						
						
							| 33 | 
							
								
							 | 
							df-3an | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) <-> ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) /\ ( j e. n /\ i = suc j ) ) )  | 
						
						
							| 34 | 
							
								33
							 | 
							imbi2i | 
							 |-  ( ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) ) <-> ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) /\ ( j e. n /\ i = suc j ) ) ) )  | 
						
						
							| 35 | 
							
								34
							 | 
							exbii | 
							 |-  ( E. j ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) ) <-> E. j ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) /\ ( j e. n /\ i = suc j ) ) ) )  | 
						
						
							| 36 | 
							
								32 35
							 | 
							mpbir | 
							 |-  E. j ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) )  | 
						
						
							| 37 | 
							
								
							 | 
							bnj213 | 
							 |-  _pred ( y , A , R ) C_ A  | 
						
						
							| 38 | 
							
								37
							 | 
							bnj226 | 
							 |-  U_ y e. ( f ` j ) _pred ( y , A , R ) C_ A  | 
						
						
							| 39 | 
							
								
							 | 
							simp21 | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) -> i e. n )  | 
						
						
							| 40 | 
							
								
							 | 
							simp3r | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) -> i = suc j )  | 
						
						
							| 41 | 
							
								
							 | 
							biid | 
							 |-  ( n e. D <-> n e. D )  | 
						
						
							| 42 | 
							
								
							 | 
							biid | 
							 |-  ( f Fn n <-> f Fn n )  | 
						
						
							| 43 | 
							
								
							 | 
							vex | 
							 |-  j e. _V  | 
						
						
							| 44 | 
							
								
							 | 
							sbcg | 
							 |-  ( j e. _V -> ( [. j / i ]. ph <-> ph ) )  | 
						
						
							| 45 | 
							
								43 44
							 | 
							ax-mp | 
							 |-  ( [. j / i ]. ph <-> ph )  | 
						
						
							| 46 | 
							
								8 45
							 | 
							bitr2i | 
							 |-  ( ph <-> ph' )  | 
						
						
							| 47 | 
							
								2 9
							 | 
							bnj1039 | 
							 |-  ( ps' <-> A. i e. _om ( suc i e. n -> ( f ` suc i ) = U_ y e. ( f ` i ) _pred ( y , A , R ) ) )  | 
						
						
							| 48 | 
							
								2 47
							 | 
							bitr4i | 
							 |-  ( ps <-> ps' )  | 
						
						
							| 49 | 
							
								41 42 46 48
							 | 
							bnj887 | 
							 |-  ( ( n e. D /\ f Fn n /\ ph /\ ps ) <-> ( n e. D /\ f Fn n /\ ph' /\ ps' ) )  | 
						
						
							| 50 | 
							
								8 9 5 10
							 | 
							bnj1040 | 
							 |-  ( ch' <-> ( n e. D /\ f Fn n /\ ph' /\ ps' ) )  | 
						
						
							| 51 | 
							
								49 5 50
							 | 
							3bitr4i | 
							 |-  ( ch <-> ch' )  | 
						
						
							| 52 | 
							
								50
							 | 
							bnj1254 | 
							 |-  ( ch' -> ps' )  | 
						
						
							| 53 | 
							
								51 52
							 | 
							sylbi | 
							 |-  ( ch -> ps' )  | 
						
						
							| 54 | 
							
								53
							 | 
							3ad2ant3 | 
							 |-  ( ( i e. n /\ ta /\ ch ) -> ps' )  | 
						
						
							| 55 | 
							
								54
							 | 
							3ad2ant2 | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) -> ps' )  | 
						
						
							| 56 | 
							
								
							 | 
							simp3l | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) -> j e. n )  | 
						
						
							| 57 | 
							
								27
							 | 
							3ad2ant2 | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) -> n e. D )  | 
						
						
							| 58 | 
							
								3
							 | 
							bnj923 | 
							 |-  ( n e. D -> n e. _om )  | 
						
						
							| 59 | 
							
								
							 | 
							elnn | 
							 |-  ( ( j e. n /\ n e. _om ) -> j e. _om )  | 
						
						
							| 60 | 
							
								58 59
							 | 
							sylan2 | 
							 |-  ( ( j e. n /\ n e. D ) -> j e. _om )  | 
						
						
							| 61 | 
							
								56 57 60
							 | 
							syl2anc | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) -> j e. _om )  | 
						
						
							| 62 | 
							
								47
							 | 
							bnj589 | 
							 |-  ( ps' <-> A. j e. _om ( suc j e. n -> ( f ` suc j ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) )  | 
						
						
							| 63 | 
							
								
							 | 
							rsp | 
							 |-  ( A. j e. _om ( suc j e. n -> ( f ` suc j ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) -> ( j e. _om -> ( suc j e. n -> ( f ` suc j ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) ) )  | 
						
						
							| 64 | 
							
								62 63
							 | 
							sylbi | 
							 |-  ( ps' -> ( j e. _om -> ( suc j e. n -> ( f ` suc j ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) ) )  | 
						
						
							| 65 | 
							
								
							 | 
							eleq1 | 
							 |-  ( i = suc j -> ( i e. n <-> suc j e. n ) )  | 
						
						
							| 66 | 
							
								
							 | 
							fveqeq2 | 
							 |-  ( i = suc j -> ( ( f ` i ) = U_ y e. ( f ` j ) _pred ( y , A , R ) <-> ( f ` suc j ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) )  | 
						
						
							| 67 | 
							
								65 66
							 | 
							imbi12d | 
							 |-  ( i = suc j -> ( ( i e. n -> ( f ` i ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) <-> ( suc j e. n -> ( f ` suc j ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) ) )  | 
						
						
							| 68 | 
							
								67
							 | 
							imbi2d | 
							 |-  ( i = suc j -> ( ( j e. _om -> ( i e. n -> ( f ` i ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) ) <-> ( j e. _om -> ( suc j e. n -> ( f ` suc j ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) ) ) )  | 
						
						
							| 69 | 
							
								64 68
							 | 
							imbitrrid | 
							 |-  ( i = suc j -> ( ps' -> ( j e. _om -> ( i e. n -> ( f ` i ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) ) ) )  | 
						
						
							| 70 | 
							
								40 55 61 69
							 | 
							syl3c | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) -> ( i e. n -> ( f ` i ) = U_ y e. ( f ` j ) _pred ( y , A , R ) ) )  | 
						
						
							| 71 | 
							
								39 70
							 | 
							mpd | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) -> ( f ` i ) = U_ y e. ( f ` j ) _pred ( y , A , R ) )  | 
						
						
							| 72 | 
							
								38 71
							 | 
							bnj1262 | 
							 |-  ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) /\ ( j e. n /\ i = suc j ) ) -> ( f ` i ) C_ A )  | 
						
						
							| 73 | 
							
								36 72
							 | 
							bnj1023 | 
							 |-  E. j ( ( i =/= (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( f ` i ) C_ A )  | 
						
						
							| 74 | 
							
								5
							 | 
							bnj1247 | 
							 |-  ( ch -> ph )  | 
						
						
							| 75 | 
							
								74
							 | 
							3ad2ant3 | 
							 |-  ( ( i e. n /\ ta /\ ch ) -> ph )  | 
						
						
							| 76 | 
							
								
							 | 
							bnj213 | 
							 |-  _pred ( X , A , R ) C_ A  | 
						
						
							| 77 | 
							
								
							 | 
							fveq2 | 
							 |-  ( i = (/) -> ( f ` i ) = ( f ` (/) ) )  | 
						
						
							| 78 | 
							
								1
							 | 
							biimpi | 
							 |-  ( ph -> ( f ` (/) ) = _pred ( X , A , R ) )  | 
						
						
							| 79 | 
							
								77 78
							 | 
							sylan9eq | 
							 |-  ( ( i = (/) /\ ph ) -> ( f ` i ) = _pred ( X , A , R ) )  | 
						
						
							| 80 | 
							
								76 79
							 | 
							bnj1262 | 
							 |-  ( ( i = (/) /\ ph ) -> ( f ` i ) C_ A )  | 
						
						
							| 81 | 
							
								75 80
							 | 
							sylan2 | 
							 |-  ( ( i = (/) /\ ( i e. n /\ ta /\ ch ) ) -> ( f ` i ) C_ A )  | 
						
						
							| 82 | 
							
								73 81
							 | 
							bnj1109 | 
							 |-  E. j ( ( i e. n /\ ta /\ ch ) -> ( f ` i ) C_ A )  | 
						
						
							| 83 | 
							
								22 82
							 | 
							bnj1131 | 
							 |-  ( ( i e. n /\ ta /\ ch ) -> ( f ` i ) C_ A )  | 
						
						
							| 84 | 
							
								83
							 | 
							3expia | 
							 |-  ( ( i e. n /\ ta ) -> ( ch -> ( f ` i ) C_ A ) )  | 
						
						
							| 85 | 
							
								84 6
							 | 
							sylibr | 
							 |-  ( ( i e. n /\ ta ) -> th )  | 
						
						
							| 86 | 
							
								3 5 7 85
							 | 
							bnj1133 | 
							 |-  ( ch -> A. i e. n th )  | 
						
						
							| 87 | 
							
								6
							 | 
							ralbii | 
							 |-  ( A. i e. n th <-> A. i e. n ( ch -> ( f ` i ) C_ A ) )  | 
						
						
							| 88 | 
							
								86 87
							 | 
							sylib | 
							 |-  ( ch -> A. i e. n ( ch -> ( f ` i ) C_ A ) )  | 
						
						
							| 89 | 
							
								
							 | 
							rsp | 
							 |-  ( A. i e. n ( ch -> ( f ` i ) C_ A ) -> ( i e. n -> ( ch -> ( f ` i ) C_ A ) ) )  | 
						
						
							| 90 | 
							
								88 89
							 | 
							syl | 
							 |-  ( ch -> ( i e. n -> ( ch -> ( f ` i ) C_ A ) ) )  | 
						
						
							| 91 | 
							
								13 14 13 90
							 | 
							syl3c | 
							 |-  ( ( ch /\ i e. n /\ Y e. ( f ` i ) ) -> ( f ` i ) C_ A )  | 
						
						
							| 92 | 
							
								
							 | 
							simp3 | 
							 |-  ( ( ch /\ i e. n /\ Y e. ( f ` i ) ) -> Y e. ( f ` i ) )  | 
						
						
							| 93 | 
							
								91 92
							 | 
							sseldd | 
							 |-  ( ( ch /\ i e. n /\ Y e. ( f ` i ) ) -> Y e. A )  | 
						
						
							| 94 | 
							
								93
							 | 
							2eximi | 
							 |-  ( E. n E. i ( ch /\ i e. n /\ Y e. ( f ` i ) ) -> E. n E. i Y e. A )  | 
						
						
							| 95 | 
							
								12 94
							 | 
							bnj593 | 
							 |-  ( Y e. _trCl ( X , A , R ) -> E. f E. n E. i Y e. A )  | 
						
						
							| 96 | 
							
								
							 | 
							19.9v | 
							 |-  ( E. f E. n E. i Y e. A <-> E. n E. i Y e. A )  | 
						
						
							| 97 | 
							
								
							 | 
							19.9v | 
							 |-  ( E. n E. i Y e. A <-> E. i Y e. A )  | 
						
						
							| 98 | 
							
								
							 | 
							19.9v | 
							 |-  ( E. i Y e. A <-> Y e. A )  | 
						
						
							| 99 | 
							
								96 97 98
							 | 
							3bitri | 
							 |-  ( E. f E. n E. i Y e. A <-> Y e. A )  | 
						
						
							| 100 | 
							
								95 99
							 | 
							sylib | 
							 |-  ( Y e. _trCl ( X , A , R ) -> Y e. A )  |