| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj1018.1 | 
							 |-  ( ph <-> ( f ` (/) ) = _pred ( X , A , R ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj1018.2 | 
							 |-  ( ps <-> A. i e. _om ( suc i e. n -> ( f ` suc i ) = U_ y e. ( f ` i ) _pred ( y , A , R ) ) )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj1018.3 | 
							 |-  ( ch <-> ( n e. D /\ f Fn n /\ ph /\ ps ) )  | 
						
						
							| 4 | 
							
								
							 | 
							bnj1018.4 | 
							 |-  ( th <-> ( R _FrSe A /\ X e. A /\ y e. _trCl ( X , A , R ) /\ z e. _pred ( y , A , R ) ) )  | 
						
						
							| 5 | 
							
								
							 | 
							bnj1018.5 | 
							 |-  ( ta <-> ( m e. _om /\ n = suc m /\ p = suc n ) )  | 
						
						
							| 6 | 
							
								
							 | 
							bnj1018.7 | 
							 |-  ( ph' <-> [. p / n ]. ph )  | 
						
						
							| 7 | 
							
								
							 | 
							bnj1018.8 | 
							 |-  ( ps' <-> [. p / n ]. ps )  | 
						
						
							| 8 | 
							
								
							 | 
							bnj1018.9 | 
							 |-  ( ch' <-> [. p / n ]. ch )  | 
						
						
							| 9 | 
							
								
							 | 
							bnj1018.10 | 
							 |-  ( ph" <-> [. G / f ]. ph' )  | 
						
						
							| 10 | 
							
								
							 | 
							bnj1018.11 | 
							 |-  ( ps" <-> [. G / f ]. ps' )  | 
						
						
							| 11 | 
							
								
							 | 
							bnj1018.12 | 
							 |-  ( ch" <-> [. G / f ]. ch' )  | 
						
						
							| 12 | 
							
								
							 | 
							bnj1018.13 | 
							 |-  D = ( _om \ { (/) } ) | 
						
						
							| 13 | 
							
								
							 | 
							bnj1018.14 | 
							 |-  B = { f | E. n e. D ( f Fn n /\ ph /\ ps ) } | 
						
						
							| 14 | 
							
								
							 | 
							bnj1018.15 | 
							 |-  C = U_ y e. ( f ` m ) _pred ( y , A , R )  | 
						
						
							| 15 | 
							
								
							 | 
							bnj1018.16 | 
							 |-  G = ( f u. { <. n , C >. } ) | 
						
						
							| 16 | 
							
								
							 | 
							bnj1018.26 | 
							 |-  ( ch" <-> ( p e. D /\ G Fn p /\ ph" /\ ps" ) )  | 
						
						
							| 17 | 
							
								
							 | 
							bnj1018.29 | 
							 |-  ( ( th /\ ch /\ ta /\ et ) -> ch" )  | 
						
						
							| 18 | 
							
								
							 | 
							bnj1018.30 | 
							 |-  ( ( th /\ ch /\ ta /\ et ) -> ( ch" /\ i e. _om /\ suc i e. p ) )  | 
						
						
							| 19 | 
							
								
							 | 
							df-bnj17 | 
							 |-  ( ( th /\ ch /\ et /\ E. p ta ) <-> ( ( th /\ ch /\ et ) /\ E. p ta ) )  | 
						
						
							| 20 | 
							
								
							 | 
							bnj258 | 
							 |-  ( ( th /\ ch /\ ta /\ et ) <-> ( ( th /\ ch /\ et ) /\ ta ) )  | 
						
						
							| 21 | 
							
								20 17
							 | 
							sylbir | 
							 |-  ( ( ( th /\ ch /\ et ) /\ ta ) -> ch" )  | 
						
						
							| 22 | 
							
								21
							 | 
							ex | 
							 |-  ( ( th /\ ch /\ et ) -> ( ta -> ch" ) )  | 
						
						
							| 23 | 
							
								22
							 | 
							eximdv | 
							 |-  ( ( th /\ ch /\ et ) -> ( E. p ta -> E. p ch" ) )  | 
						
						
							| 24 | 
							
								3 8 11 13 15
							 | 
							bnj985 | 
							 |-  ( G e. B <-> E. p ch" )  | 
						
						
							| 25 | 
							
								23 24
							 | 
							imbitrrdi | 
							 |-  ( ( th /\ ch /\ et ) -> ( E. p ta -> G e. B ) )  | 
						
						
							| 26 | 
							
								25
							 | 
							imp | 
							 |-  ( ( ( th /\ ch /\ et ) /\ E. p ta ) -> G e. B )  | 
						
						
							| 27 | 
							
								19 26
							 | 
							sylbi | 
							 |-  ( ( th /\ ch /\ et /\ E. p ta ) -> G e. B )  | 
						
						
							| 28 | 
							
								
							 | 
							bnj1019 | 
							 |-  ( E. p ( th /\ ch /\ ta /\ et ) <-> ( th /\ ch /\ et /\ E. p ta ) )  | 
						
						
							| 29 | 
							
								18
							 | 
							simp3d | 
							 |-  ( ( th /\ ch /\ ta /\ et ) -> suc i e. p )  | 
						
						
							| 30 | 
							
								16
							 | 
							bnj1235 | 
							 |-  ( ch" -> G Fn p )  | 
						
						
							| 31 | 
							
								
							 | 
							fndm | 
							 |-  ( G Fn p -> dom G = p )  | 
						
						
							| 32 | 
							
								17 30 31
							 | 
							3syl | 
							 |-  ( ( th /\ ch /\ ta /\ et ) -> dom G = p )  | 
						
						
							| 33 | 
							
								29 32
							 | 
							eleqtrrd | 
							 |-  ( ( th /\ ch /\ ta /\ et ) -> suc i e. dom G )  | 
						
						
							| 34 | 
							
								33
							 | 
							exlimiv | 
							 |-  ( E. p ( th /\ ch /\ ta /\ et ) -> suc i e. dom G )  | 
						
						
							| 35 | 
							
								28 34
							 | 
							sylbir | 
							 |-  ( ( th /\ ch /\ et /\ E. p ta ) -> suc i e. dom G )  | 
						
						
							| 36 | 
							
								15
							 | 
							bnj918 | 
							 |-  G e. _V  | 
						
						
							| 37 | 
							
								
							 | 
							vex | 
							 |-  i e. _V  | 
						
						
							| 38 | 
							
								37
							 | 
							sucex | 
							 |-  suc i e. _V  | 
						
						
							| 39 | 
							
								1 2 12 13 36 38
							 | 
							bnj1015 | 
							 |-  ( ( G e. B /\ suc i e. dom G ) -> ( G ` suc i ) C_ _trCl ( X , A , R ) )  | 
						
						
							| 40 | 
							
								27 35 39
							 | 
							syl2anc | 
							 |-  ( ( th /\ ch /\ et /\ E. p ta ) -> ( G ` suc i ) C_ _trCl ( X , A , R ) )  |