| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj1020.1 | 
							⊢ ( 𝜑  ↔  ( 𝑓 ‘ ∅ )  =   pred ( 𝑋 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj1020.2 | 
							⊢ ( 𝜓  ↔  ∀ 𝑖  ∈  ω ( suc  𝑖  ∈  𝑛  →  ( 𝑓 ‘ suc  𝑖 )  =  ∪  𝑦  ∈  ( 𝑓 ‘ 𝑖 )  pred ( 𝑦 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj1020.3 | 
							⊢ ( 𝜒  ↔  ( 𝑛  ∈  𝐷  ∧  𝑓  Fn  𝑛  ∧  𝜑  ∧  𝜓 ) )  | 
						
						
							| 4 | 
							
								
							 | 
							bnj1020.4 | 
							⊢ ( 𝜃  ↔  ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴  ∧  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  ∧  𝑧  ∈   pred ( 𝑦 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 5 | 
							
								
							 | 
							bnj1020.5 | 
							⊢ ( 𝜏  ↔  ( 𝑚  ∈  ω  ∧  𝑛  =  suc  𝑚  ∧  𝑝  =  suc  𝑛 ) )  | 
						
						
							| 6 | 
							
								
							 | 
							bnj1020.6 | 
							⊢ ( 𝜂  ↔  ( 𝑖  ∈  𝑛  ∧  𝑦  ∈  ( 𝑓 ‘ 𝑖 ) ) )  | 
						
						
							| 7 | 
							
								
							 | 
							bnj1020.7 | 
							⊢ ( 𝜑′  ↔  [ 𝑝  /  𝑛 ] 𝜑 )  | 
						
						
							| 8 | 
							
								
							 | 
							bnj1020.8 | 
							⊢ ( 𝜓′  ↔  [ 𝑝  /  𝑛 ] 𝜓 )  | 
						
						
							| 9 | 
							
								
							 | 
							bnj1020.9 | 
							⊢ ( 𝜒′  ↔  [ 𝑝  /  𝑛 ] 𝜒 )  | 
						
						
							| 10 | 
							
								
							 | 
							bnj1020.10 | 
							⊢ ( 𝜑″  ↔  [ 𝐺  /  𝑓 ] 𝜑′ )  | 
						
						
							| 11 | 
							
								
							 | 
							bnj1020.11 | 
							⊢ ( 𝜓″  ↔  [ 𝐺  /  𝑓 ] 𝜓′ )  | 
						
						
							| 12 | 
							
								
							 | 
							bnj1020.12 | 
							⊢ ( 𝜒″  ↔  [ 𝐺  /  𝑓 ] 𝜒′ )  | 
						
						
							| 13 | 
							
								
							 | 
							bnj1020.13 | 
							⊢ 𝐷  =  ( ω  ∖  { ∅ } )  | 
						
						
							| 14 | 
							
								
							 | 
							bnj1020.14 | 
							⊢ 𝐵  =  { 𝑓  ∣  ∃ 𝑛  ∈  𝐷 ( 𝑓  Fn  𝑛  ∧  𝜑  ∧  𝜓 ) }  | 
						
						
							| 15 | 
							
								
							 | 
							bnj1020.15 | 
							⊢ 𝐶  =  ∪  𝑦  ∈  ( 𝑓 ‘ 𝑚 )  pred ( 𝑦 ,  𝐴 ,  𝑅 )  | 
						
						
							| 16 | 
							
								
							 | 
							bnj1020.16 | 
							⊢ 𝐺  =  ( 𝑓  ∪  { 〈 𝑛 ,  𝐶 〉 } )  | 
						
						
							| 17 | 
							
								
							 | 
							bnj1020.26 | 
							⊢ ( 𝜒″  ↔  ( 𝑝  ∈  𝐷  ∧  𝐺  Fn  𝑝  ∧  𝜑″  ∧  𝜓″ ) )  | 
						
						
							| 18 | 
							
								
							 | 
							bnj1019 | 
							⊢ ( ∃ 𝑝 ( 𝜃  ∧  𝜒  ∧  𝜏  ∧  𝜂 )  ↔  ( 𝜃  ∧  𝜒  ∧  𝜂  ∧  ∃ 𝑝 𝜏 ) )  | 
						
						
							| 19 | 
							
								1 2 3 4 5 7 8 9 10 11 12 13 14 15 16
							 | 
							bnj998 | 
							⊢ ( ( 𝜃  ∧  𝜒  ∧  𝜏  ∧  𝜂 )  →  𝜒″ )  | 
						
						
							| 20 | 
							
								3 5 6 13 19
							 | 
							bnj1001 | 
							⊢ ( ( 𝜃  ∧  𝜒  ∧  𝜏  ∧  𝜂 )  →  ( 𝜒″  ∧  𝑖  ∈  ω  ∧  suc  𝑖  ∈  𝑝 ) )  | 
						
						
							| 21 | 
							
								1 2 3 4 5 6 7 8 9 10 11 12 13 15 16 20
							 | 
							bnj1006 | 
							⊢ ( ( 𝜃  ∧  𝜒  ∧  𝜏  ∧  𝜂 )  →   pred ( 𝑦 ,  𝐴 ,  𝑅 )  ⊆  ( 𝐺 ‘ suc  𝑖 ) )  | 
						
						
							| 22 | 
							
								21
							 | 
							exlimiv | 
							⊢ ( ∃ 𝑝 ( 𝜃  ∧  𝜒  ∧  𝜏  ∧  𝜂 )  →   pred ( 𝑦 ,  𝐴 ,  𝑅 )  ⊆  ( 𝐺 ‘ suc  𝑖 ) )  | 
						
						
							| 23 | 
							
								18 22
							 | 
							sylbir | 
							⊢ ( ( 𝜃  ∧  𝜒  ∧  𝜂  ∧  ∃ 𝑝 𝜏 )  →   pred ( 𝑦 ,  𝐴 ,  𝑅 )  ⊆  ( 𝐺 ‘ suc  𝑖 ) )  | 
						
						
							| 24 | 
							
								1 2 3 4 5 7 8 9 10 11 12 13 14 15 16 17 19 20
							 | 
							bnj1018 | 
							⊢ ( ( 𝜃  ∧  𝜒  ∧  𝜂  ∧  ∃ 𝑝 𝜏 )  →  ( 𝐺 ‘ suc  𝑖 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 25 | 
							
								23 24
							 | 
							sstrd | 
							⊢ ( ( 𝜃  ∧  𝜒  ∧  𝜂  ∧  ∃ 𝑝 𝜏 )  →   pred ( 𝑦 ,  𝐴 ,  𝑅 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  |