| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj996.1 | 
							⊢ ( 𝜑  ↔  ( 𝑓 ‘ ∅ )  =   pred ( 𝑋 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj996.2 | 
							⊢ ( 𝜓  ↔  ∀ 𝑖  ∈  ω ( suc  𝑖  ∈  𝑛  →  ( 𝑓 ‘ suc  𝑖 )  =  ∪  𝑦  ∈  ( 𝑓 ‘ 𝑖 )  pred ( 𝑦 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj996.3 | 
							⊢ ( 𝜒  ↔  ( 𝑛  ∈  𝐷  ∧  𝑓  Fn  𝑛  ∧  𝜑  ∧  𝜓 ) )  | 
						
						
							| 4 | 
							
								
							 | 
							bnj996.4 | 
							⊢ ( 𝜃  ↔  ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴  ∧  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  ∧  𝑧  ∈   pred ( 𝑦 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 5 | 
							
								
							 | 
							bnj996.5 | 
							⊢ ( 𝜏  ↔  ( 𝑚  ∈  ω  ∧  𝑛  =  suc  𝑚  ∧  𝑝  =  suc  𝑛 ) )  | 
						
						
							| 6 | 
							
								
							 | 
							bnj996.6 | 
							⊢ ( 𝜂  ↔  ( 𝑖  ∈  𝑛  ∧  𝑦  ∈  ( 𝑓 ‘ 𝑖 ) ) )  | 
						
						
							| 7 | 
							
								
							 | 
							bnj996.13 | 
							⊢ 𝐷  =  ( ω  ∖  { ∅ } )  | 
						
						
							| 8 | 
							
								
							 | 
							bnj996.14 | 
							⊢ 𝐵  =  { 𝑓  ∣  ∃ 𝑛  ∈  𝐷 ( 𝑓  Fn  𝑛  ∧  𝜑  ∧  𝜓 ) }  | 
						
						
							| 9 | 
							
								1 2 7 8 3
							 | 
							bnj917 | 
							⊢ ( 𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  →  ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ( 𝜒  ∧  𝑖  ∈  𝑛  ∧  𝑦  ∈  ( 𝑓 ‘ 𝑖 ) ) )  | 
						
						
							| 10 | 
							
								4 9
							 | 
							bnj771 | 
							⊢ ( 𝜃  →  ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ( 𝜒  ∧  𝑖  ∈  𝑛  ∧  𝑦  ∈  ( 𝑓 ‘ 𝑖 ) ) )  | 
						
						
							| 11 | 
							
								
							 | 
							3anass | 
							⊢ ( ( 𝜒  ∧  𝑖  ∈  𝑛  ∧  𝑦  ∈  ( 𝑓 ‘ 𝑖 ) )  ↔  ( 𝜒  ∧  ( 𝑖  ∈  𝑛  ∧  𝑦  ∈  ( 𝑓 ‘ 𝑖 ) ) ) )  | 
						
						
							| 12 | 
							
								6
							 | 
							anbi2i | 
							⊢ ( ( 𝜒  ∧  𝜂 )  ↔  ( 𝜒  ∧  ( 𝑖  ∈  𝑛  ∧  𝑦  ∈  ( 𝑓 ‘ 𝑖 ) ) ) )  | 
						
						
							| 13 | 
							
								11 12
							 | 
							bitr4i | 
							⊢ ( ( 𝜒  ∧  𝑖  ∈  𝑛  ∧  𝑦  ∈  ( 𝑓 ‘ 𝑖 ) )  ↔  ( 𝜒  ∧  𝜂 ) )  | 
						
						
							| 14 | 
							
								13
							 | 
							3exbii | 
							⊢ ( ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ( 𝜒  ∧  𝑖  ∈  𝑛  ∧  𝑦  ∈  ( 𝑓 ‘ 𝑖 ) )  ↔  ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ( 𝜒  ∧  𝜂 ) )  | 
						
						
							| 15 | 
							
								10 14
							 | 
							sylib | 
							⊢ ( 𝜃  →  ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ( 𝜒  ∧  𝜂 ) )  | 
						
						
							| 16 | 
							
								3 7 5
							 | 
							bnj986 | 
							⊢ ( 𝜒  →  ∃ 𝑚 ∃ 𝑝 𝜏 )  | 
						
						
							| 17 | 
							
								16
							 | 
							ancli | 
							⊢ ( 𝜒  →  ( 𝜒  ∧  ∃ 𝑚 ∃ 𝑝 𝜏 ) )  | 
						
						
							| 18 | 
							
								
							 | 
							19.42vv | 
							⊢ ( ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏 )  ↔  ( 𝜒  ∧  ∃ 𝑚 ∃ 𝑝 𝜏 ) )  | 
						
						
							| 19 | 
							
								17 18
							 | 
							sylibr | 
							⊢ ( 𝜒  →  ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏 ) )  | 
						
						
							| 20 | 
							
								19
							 | 
							anim1i | 
							⊢ ( ( 𝜒  ∧  𝜂 )  →  ( ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏 )  ∧  𝜂 ) )  | 
						
						
							| 21 | 
							
								
							 | 
							19.41vv | 
							⊢ ( ∃ 𝑚 ∃ 𝑝 ( ( 𝜒  ∧  𝜏 )  ∧  𝜂 )  ↔  ( ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏 )  ∧  𝜂 ) )  | 
						
						
							| 22 | 
							
								20 21
							 | 
							sylibr | 
							⊢ ( ( 𝜒  ∧  𝜂 )  →  ∃ 𝑚 ∃ 𝑝 ( ( 𝜒  ∧  𝜏 )  ∧  𝜂 ) )  | 
						
						
							| 23 | 
							
								
							 | 
							df-3an | 
							⊢ ( ( 𝜒  ∧  𝜏  ∧  𝜂 )  ↔  ( ( 𝜒  ∧  𝜏 )  ∧  𝜂 ) )  | 
						
						
							| 24 | 
							
								23
							 | 
							2exbii | 
							⊢ ( ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 )  ↔  ∃ 𝑚 ∃ 𝑝 ( ( 𝜒  ∧  𝜏 )  ∧  𝜂 ) )  | 
						
						
							| 25 | 
							
								22 24
							 | 
							sylibr | 
							⊢ ( ( 𝜒  ∧  𝜂 )  →  ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  | 
						
						
							| 26 | 
							
								25
							 | 
							2eximi | 
							⊢ ( ∃ 𝑛 ∃ 𝑖 ( 𝜒  ∧  𝜂 )  →  ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  | 
						
						
							| 27 | 
							
								15 26
							 | 
							bnj593 | 
							⊢ ( 𝜃  →  ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  | 
						
						
							| 28 | 
							
								
							 | 
							19.37v | 
							⊢ ( ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  ↔  ( 𝜃  →  ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) ) )  | 
						
						
							| 29 | 
							
								28
							 | 
							exbii | 
							⊢ ( ∃ 𝑚 ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  ↔  ∃ 𝑚 ( 𝜃  →  ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) ) )  | 
						
						
							| 30 | 
							
								29
							 | 
							bnj132 | 
							⊢ ( ∃ 𝑚 ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  ↔  ( 𝜃  →  ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) ) )  | 
						
						
							| 31 | 
							
								30
							 | 
							exbii | 
							⊢ ( ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  ↔  ∃ 𝑖 ( 𝜃  →  ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) ) )  | 
						
						
							| 32 | 
							
								31
							 | 
							bnj132 | 
							⊢ ( ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  ↔  ( 𝜃  →  ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) ) )  | 
						
						
							| 33 | 
							
								32
							 | 
							exbii | 
							⊢ ( ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  ↔  ∃ 𝑛 ( 𝜃  →  ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) ) )  | 
						
						
							| 34 | 
							
								33
							 | 
							bnj132 | 
							⊢ ( ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  ↔  ( 𝜃  →  ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) ) )  | 
						
						
							| 35 | 
							
								34
							 | 
							exbii | 
							⊢ ( ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  ↔  ∃ 𝑓 ( 𝜃  →  ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) ) )  | 
						
						
							| 36 | 
							
								35
							 | 
							bnj132 | 
							⊢ ( ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  ↔  ( 𝜃  →  ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜒  ∧  𝜏  ∧  𝜂 ) ) )  | 
						
						
							| 37 | 
							
								27 36
							 | 
							mpbir | 
							⊢ ∃ 𝑓 ∃ 𝑛 ∃ 𝑖 ∃ 𝑚 ∃ 𝑝 ( 𝜃  →  ( 𝜒  ∧  𝜏  ∧  𝜂 ) )  |