| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							nfseq.1 | 
							 |-  F/_ x M  | 
						
						
							| 2 | 
							
								
							 | 
							nfseq.2 | 
							 |-  F/_ x .+  | 
						
						
							| 3 | 
							
								
							 | 
							nfseq.3 | 
							 |-  F/_ x F  | 
						
						
							| 4 | 
							
								
							 | 
							df-seq | 
							 |-  seq M ( .+ , F ) = ( rec ( ( z e. _V , w e. _V |-> <. ( z + 1 ) , ( w .+ ( F ` ( z + 1 ) ) ) >. ) , <. M , ( F ` M ) >. ) " _om )  | 
						
						
							| 5 | 
							
								
							 | 
							nfcv | 
							 |-  F/_ x _V  | 
						
						
							| 6 | 
							
								
							 | 
							nfcv | 
							 |-  F/_ x ( z + 1 )  | 
						
						
							| 7 | 
							
								
							 | 
							nfcv | 
							 |-  F/_ x w  | 
						
						
							| 8 | 
							
								3 6
							 | 
							nffv | 
							 |-  F/_ x ( F ` ( z + 1 ) )  | 
						
						
							| 9 | 
							
								7 2 8
							 | 
							nfov | 
							 |-  F/_ x ( w .+ ( F ` ( z + 1 ) ) )  | 
						
						
							| 10 | 
							
								6 9
							 | 
							nfop | 
							 |-  F/_ x <. ( z + 1 ) , ( w .+ ( F ` ( z + 1 ) ) ) >.  | 
						
						
							| 11 | 
							
								5 5 10
							 | 
							nfmpo | 
							 |-  F/_ x ( z e. _V , w e. _V |-> <. ( z + 1 ) , ( w .+ ( F ` ( z + 1 ) ) ) >. )  | 
						
						
							| 12 | 
							
								3 1
							 | 
							nffv | 
							 |-  F/_ x ( F ` M )  | 
						
						
							| 13 | 
							
								1 12
							 | 
							nfop | 
							 |-  F/_ x <. M , ( F ` M ) >.  | 
						
						
							| 14 | 
							
								11 13
							 | 
							nfrdg | 
							 |-  F/_ x rec ( ( z e. _V , w e. _V |-> <. ( z + 1 ) , ( w .+ ( F ` ( z + 1 ) ) ) >. ) , <. M , ( F ` M ) >. )  | 
						
						
							| 15 | 
							
								
							 | 
							nfcv | 
							 |-  F/_ x _om  | 
						
						
							| 16 | 
							
								14 15
							 | 
							nfima | 
							 |-  F/_ x ( rec ( ( z e. _V , w e. _V |-> <. ( z + 1 ) , ( w .+ ( F ` ( z + 1 ) ) ) >. ) , <. M , ( F ` M ) >. ) " _om )  | 
						
						
							| 17 | 
							
								4 16
							 | 
							nfcxfr | 
							 |-  F/_ x seq M ( .+ , F )  |