| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj1518.1 | 
							⊢ 𝐵  =  { 𝑑  ∣  ( 𝑑  ⊆  𝐴  ∧  ∀ 𝑥  ∈  𝑑  pred ( 𝑥 ,  𝐴 ,  𝑅 )  ⊆  𝑑 ) }  | 
						
						
							| 2 | 
							
								
							 | 
							bnj1518.2 | 
							⊢ 𝑌  =  〈 𝑥 ,  ( 𝑓  ↾   pred ( 𝑥 ,  𝐴 ,  𝑅 ) ) 〉  | 
						
						
							| 3 | 
							
								
							 | 
							bnj1518.3 | 
							⊢ 𝐶  =  { 𝑓  ∣  ∃ 𝑑  ∈  𝐵 ( 𝑓  Fn  𝑑  ∧  ∀ 𝑥  ∈  𝑑 ( 𝑓 ‘ 𝑥 )  =  ( 𝐺 ‘ 𝑌 ) ) }  | 
						
						
							| 4 | 
							
								
							 | 
							bnj1518.4 | 
							⊢ 𝐹  =  ∪  𝐶  | 
						
						
							| 5 | 
							
								
							 | 
							bnj1518.5 | 
							⊢ ( 𝜑  ↔  ( 𝑅  FrSe  𝐴  ∧  𝑥  ∈  𝐴 ) )  | 
						
						
							| 6 | 
							
								
							 | 
							bnj1518.6 | 
							⊢ ( 𝜓  ↔  ( 𝜑  ∧  𝑓  ∈  𝐶  ∧  𝑥  ∈  dom  𝑓 ) )  | 
						
						
							| 7 | 
							
								
							 | 
							nfv | 
							⊢ Ⅎ 𝑑 𝜑  | 
						
						
							| 8 | 
							
								
							 | 
							nfre1 | 
							⊢ Ⅎ 𝑑 ∃ 𝑑  ∈  𝐵 ( 𝑓  Fn  𝑑  ∧  ∀ 𝑥  ∈  𝑑 ( 𝑓 ‘ 𝑥 )  =  ( 𝐺 ‘ 𝑌 ) )  | 
						
						
							| 9 | 
							
								8
							 | 
							nfab | 
							⊢ Ⅎ 𝑑 { 𝑓  ∣  ∃ 𝑑  ∈  𝐵 ( 𝑓  Fn  𝑑  ∧  ∀ 𝑥  ∈  𝑑 ( 𝑓 ‘ 𝑥 )  =  ( 𝐺 ‘ 𝑌 ) ) }  | 
						
						
							| 10 | 
							
								3 9
							 | 
							nfcxfr | 
							⊢ Ⅎ 𝑑 𝐶  | 
						
						
							| 11 | 
							
								10
							 | 
							nfcri | 
							⊢ Ⅎ 𝑑 𝑓  ∈  𝐶  | 
						
						
							| 12 | 
							
								
							 | 
							nfv | 
							⊢ Ⅎ 𝑑 𝑥  ∈  dom  𝑓  | 
						
						
							| 13 | 
							
								7 11 12
							 | 
							nf3an | 
							⊢ Ⅎ 𝑑 ( 𝜑  ∧  𝑓  ∈  𝐶  ∧  𝑥  ∈  dom  𝑓 )  | 
						
						
							| 14 | 
							
								6 13
							 | 
							nfxfr | 
							⊢ Ⅎ 𝑑 𝜓  | 
						
						
							| 15 | 
							
								14
							 | 
							nf5ri | 
							⊢ ( 𝜓  →  ∀ 𝑑 𝜓 )  |