| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj910.1 | 
							 |-  ( ph <-> ( f ` (/) ) = _pred ( X , A , R ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj910.2 | 
							 |-  ( ps <-> A. i e. _om ( suc i e. n -> ( f ` suc i ) = U_ y e. ( f ` i ) _pred ( y , A , R ) ) )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj910.3 | 
							 |-  ( ch <-> ( n e. D /\ f Fn n /\ ph /\ ps ) )  | 
						
						
							| 4 | 
							
								
							 | 
							bnj910.4 | 
							 |-  ( ph' <-> [. p / n ]. ph )  | 
						
						
							| 5 | 
							
								
							 | 
							bnj910.5 | 
							 |-  ( ps' <-> [. p / n ]. ps )  | 
						
						
							| 6 | 
							
								
							 | 
							bnj910.6 | 
							 |-  ( ch' <-> [. p / n ]. ch )  | 
						
						
							| 7 | 
							
								
							 | 
							bnj910.7 | 
							 |-  ( ph" <-> [. G / f ]. ph' )  | 
						
						
							| 8 | 
							
								
							 | 
							bnj910.8 | 
							 |-  ( ps" <-> [. G / f ]. ps' )  | 
						
						
							| 9 | 
							
								
							 | 
							bnj910.9 | 
							 |-  ( ch" <-> [. G / f ]. ch' )  | 
						
						
							| 10 | 
							
								
							 | 
							bnj910.10 | 
							 |-  D = ( _om \ { (/) } ) | 
						
						
							| 11 | 
							
								
							 | 
							bnj910.11 | 
							 |-  B = { f | E. n e. D ( f Fn n /\ ph /\ ps ) } | 
						
						
							| 12 | 
							
								
							 | 
							bnj910.12 | 
							 |-  C = U_ y e. ( f ` m ) _pred ( y , A , R )  | 
						
						
							| 13 | 
							
								
							 | 
							bnj910.13 | 
							 |-  G = ( f u. { <. n , C >. } ) | 
						
						
							| 14 | 
							
								
							 | 
							bnj910.14 | 
							 |-  ( ta <-> ( f Fn n /\ ph /\ ps ) )  | 
						
						
							| 15 | 
							
								
							 | 
							bnj910.15 | 
							 |-  ( si <-> ( n e. D /\ p = suc n /\ m e. n ) )  | 
						
						
							| 16 | 
							
								3 10
							 | 
							bnj970 | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) ) -> p e. D )  | 
						
						
							| 17 | 
							
								1 2 3 10 12 14 15
							 | 
							bnj969 | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) ) -> C e. _V )  | 
						
						
							| 18 | 
							
								
							 | 
							simpr3 | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) ) -> p = suc n )  | 
						
						
							| 19 | 
							
								3
							 | 
							bnj1235 | 
							 |-  ( ch -> f Fn n )  | 
						
						
							| 20 | 
							
								19
							 | 
							3ad2ant1 | 
							 |-  ( ( ch /\ n = suc m /\ p = suc n ) -> f Fn n )  | 
						
						
							| 21 | 
							
								20
							 | 
							adantl | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) ) -> f Fn n )  | 
						
						
							| 22 | 
							
								13
							 | 
							bnj941 | 
							 |-  ( C e. _V -> ( ( p = suc n /\ f Fn n ) -> G Fn p ) )  | 
						
						
							| 23 | 
							
								22
							 | 
							3impib | 
							 |-  ( ( C e. _V /\ p = suc n /\ f Fn n ) -> G Fn p )  | 
						
						
							| 24 | 
							
								17 18 21 23
							 | 
							syl3anc | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) ) -> G Fn p )  | 
						
						
							| 25 | 
							
								1 2 3 4 7 10 12 13 14 15
							 | 
							bnj944 | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) ) -> ph" )  | 
						
						
							| 26 | 
							
								2 3 10 12 13 17
							 | 
							bnj967 | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) /\ ( i e. _om /\ suc i e. p /\ suc i e. n ) ) -> ( G ` suc i ) = U_ y e. ( G ` i ) _pred ( y , A , R ) )  | 
						
						
							| 27 | 
							
								3 10 12 13 17 24
							 | 
							bnj966 | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) /\ ( i e. _om /\ suc i e. p /\ n = suc i ) ) -> ( G ` suc i ) = U_ y e. ( G ` i ) _pred ( y , A , R ) )  | 
						
						
							| 28 | 
							
								2 3 5 8 12 13 26 27
							 | 
							bnj964 | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) ) -> ps" )  | 
						
						
							| 29 | 
							
								16 24 25 28
							 | 
							bnj951 | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) ) -> ( p e. D /\ G Fn p /\ ph" /\ ps" ) )  | 
						
						
							| 30 | 
							
								
							 | 
							vex | 
							 |-  p e. _V  | 
						
						
							| 31 | 
							
								3 4 5 6 30
							 | 
							bnj919 | 
							 |-  ( ch' <-> ( p e. D /\ f Fn p /\ ph' /\ ps' ) )  | 
						
						
							| 32 | 
							
								13
							 | 
							bnj918 | 
							 |-  G e. _V  | 
						
						
							| 33 | 
							
								31 7 8 9 32
							 | 
							bnj976 | 
							 |-  ( ch" <-> ( p e. D /\ G Fn p /\ ph" /\ ps" ) )  | 
						
						
							| 34 | 
							
								29 33
							 | 
							sylibr | 
							 |-  ( ( ( R _FrSe A /\ X e. A ) /\ ( ch /\ n = suc m /\ p = suc n ) ) -> ch" )  |