| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj1519.1 | 
							 |-  B = { d | ( d C_ A /\ A. x e. d _pred ( x , A , R ) C_ d ) } | 
						
						
							| 2 | 
							
								
							 | 
							bnj1519.2 | 
							 |-  Y = <. x , ( f |` _pred ( x , A , R ) ) >.  | 
						
						
							| 3 | 
							
								
							 | 
							bnj1519.3 | 
							 |-  C = { f | E. d e. B ( f Fn d /\ A. x e. d ( f ` x ) = ( G ` Y ) ) } | 
						
						
							| 4 | 
							
								
							 | 
							bnj1519.4 | 
							 |-  F = U. C  | 
						
						
							| 5 | 
							
								
							 | 
							nfre1 | 
							 |-  F/ d E. d e. B ( f Fn d /\ A. x e. d ( f ` x ) = ( G ` Y ) )  | 
						
						
							| 6 | 
							
								5
							 | 
							nfab | 
							 |-  F/_ d { f | E. d e. B ( f Fn d /\ A. x e. d ( f ` x ) = ( G ` Y ) ) } | 
						
						
							| 7 | 
							
								3 6
							 | 
							nfcxfr | 
							 |-  F/_ d C  | 
						
						
							| 8 | 
							
								7
							 | 
							nfuni | 
							 |-  F/_ d U. C  | 
						
						
							| 9 | 
							
								4 8
							 | 
							nfcxfr | 
							 |-  F/_ d F  | 
						
						
							| 10 | 
							
								
							 | 
							nfcv | 
							 |-  F/_ d x  | 
						
						
							| 11 | 
							
								9 10
							 | 
							nffv | 
							 |-  F/_ d ( F ` x )  | 
						
						
							| 12 | 
							
								
							 | 
							nfcv | 
							 |-  F/_ d G  | 
						
						
							| 13 | 
							
								
							 | 
							nfcv | 
							 |-  F/_ d _pred ( x , A , R )  | 
						
						
							| 14 | 
							
								9 13
							 | 
							nfres | 
							 |-  F/_ d ( F |` _pred ( x , A , R ) )  | 
						
						
							| 15 | 
							
								10 14
							 | 
							nfop | 
							 |-  F/_ d <. x , ( F |` _pred ( x , A , R ) ) >.  | 
						
						
							| 16 | 
							
								12 15
							 | 
							nffv | 
							 |-  F/_ d ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. )  | 
						
						
							| 17 | 
							
								11 16
							 | 
							nfeq | 
							 |-  F/ d ( F ` x ) = ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. )  | 
						
						
							| 18 | 
							
								17
							 | 
							nf5ri | 
							 |-  ( ( F ` x ) = ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. ) -> A. d ( F ` x ) = ( G ` <. x , ( F |` _pred ( x , A , R ) ) >. ) )  |