| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj554.19 | 
							⊢ ( 𝜂  ↔  ( 𝑚  ∈  𝐷  ∧  𝑛  =  suc  𝑚  ∧  𝑝  ∈  ω  ∧  𝑚  =  suc  𝑝 ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj554.20 | 
							⊢ ( 𝜁  ↔  ( 𝑖  ∈  ω  ∧  suc  𝑖  ∈  𝑛  ∧  𝑚  =  suc  𝑖 ) )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj554.21 | 
							⊢ 𝐾  =  ∪  𝑦  ∈  ( 𝐺 ‘ 𝑖 )  pred ( 𝑦 ,  𝐴 ,  𝑅 )  | 
						
						
							| 4 | 
							
								
							 | 
							bnj554.22 | 
							⊢ 𝐿  =  ∪  𝑦  ∈  ( 𝐺 ‘ 𝑝 )  pred ( 𝑦 ,  𝐴 ,  𝑅 )  | 
						
						
							| 5 | 
							
								
							 | 
							bnj554.23 | 
							⊢ 𝐾  =  ∪  𝑦  ∈  ( 𝐺 ‘ 𝑖 )  pred ( 𝑦 ,  𝐴 ,  𝑅 )  | 
						
						
							| 6 | 
							
								
							 | 
							bnj554.24 | 
							⊢ 𝐿  =  ∪  𝑦  ∈  ( 𝐺 ‘ 𝑝 )  pred ( 𝑦 ,  𝐴 ,  𝑅 )  | 
						
						
							| 7 | 
							
								1
							 | 
							bnj1254 | 
							⊢ ( 𝜂  →  𝑚  =  suc  𝑝 )  | 
						
						
							| 8 | 
							
								2
							 | 
							simp3bi | 
							⊢ ( 𝜁  →  𝑚  =  suc  𝑖 )  | 
						
						
							| 9 | 
							
								
							 | 
							simpr | 
							⊢ ( ( 𝑚  =  suc  𝑝  ∧  𝑚  =  suc  𝑖 )  →  𝑚  =  suc  𝑖 )  | 
						
						
							| 10 | 
							
								
							 | 
							bnj551 | 
							⊢ ( ( 𝑚  =  suc  𝑝  ∧  𝑚  =  suc  𝑖 )  →  𝑝  =  𝑖 )  | 
						
						
							| 11 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑚  =  suc  𝑖  →  ( 𝐺 ‘ 𝑚 )  =  ( 𝐺 ‘ suc  𝑖 ) )  | 
						
						
							| 12 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑝  =  𝑖  →  ( 𝐺 ‘ 𝑝 )  =  ( 𝐺 ‘ 𝑖 ) )  | 
						
						
							| 13 | 
							
								
							 | 
							iuneq1 | 
							⊢ ( ( 𝐺 ‘ 𝑝 )  =  ( 𝐺 ‘ 𝑖 )  →  ∪  𝑦  ∈  ( 𝐺 ‘ 𝑝 )  pred ( 𝑦 ,  𝐴 ,  𝑅 )  =  ∪  𝑦  ∈  ( 𝐺 ‘ 𝑖 )  pred ( 𝑦 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 14 | 
							
								13 6 5
							 | 
							3eqtr4g | 
							⊢ ( ( 𝐺 ‘ 𝑝 )  =  ( 𝐺 ‘ 𝑖 )  →  𝐿  =  𝐾 )  | 
						
						
							| 15 | 
							
								12 14
							 | 
							syl | 
							⊢ ( 𝑝  =  𝑖  →  𝐿  =  𝐾 )  | 
						
						
							| 16 | 
							
								11 15
							 | 
							eqeqan12d | 
							⊢ ( ( 𝑚  =  suc  𝑖  ∧  𝑝  =  𝑖 )  →  ( ( 𝐺 ‘ 𝑚 )  =  𝐿  ↔  ( 𝐺 ‘ suc  𝑖 )  =  𝐾 ) )  | 
						
						
							| 17 | 
							
								9 10 16
							 | 
							syl2anc | 
							⊢ ( ( 𝑚  =  suc  𝑝  ∧  𝑚  =  suc  𝑖 )  →  ( ( 𝐺 ‘ 𝑚 )  =  𝐿  ↔  ( 𝐺 ‘ suc  𝑖 )  =  𝐾 ) )  | 
						
						
							| 18 | 
							
								7 8 17
							 | 
							syl2an | 
							⊢ ( ( 𝜂  ∧  𝜁 )  →  ( ( 𝐺 ‘ 𝑚 )  =  𝐿  ↔  ( 𝐺 ‘ suc  𝑖 )  =  𝐾 ) )  |