| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj1015.1 | 
							⊢ ( 𝜑  ↔  ( 𝑓 ‘ ∅ )  =   pred ( 𝑋 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj1015.2 | 
							⊢ ( 𝜓  ↔  ∀ 𝑖  ∈  ω ( suc  𝑖  ∈  𝑛  →  ( 𝑓 ‘ suc  𝑖 )  =  ∪  𝑦  ∈  ( 𝑓 ‘ 𝑖 )  pred ( 𝑦 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj1015.13 | 
							⊢ 𝐷  =  ( ω  ∖  { ∅ } )  | 
						
						
							| 4 | 
							
								
							 | 
							bnj1015.14 | 
							⊢ 𝐵  =  { 𝑓  ∣  ∃ 𝑛  ∈  𝐷 ( 𝑓  Fn  𝑛  ∧  𝜑  ∧  𝜓 ) }  | 
						
						
							| 5 | 
							
								
							 | 
							bnj1015.15 | 
							⊢ 𝐺  ∈  𝑉  | 
						
						
							| 6 | 
							
								
							 | 
							bnj1015.16 | 
							⊢ 𝐽  ∈  𝑉  | 
						
						
							| 7 | 
							
								6
							 | 
							elexi | 
							⊢ 𝐽  ∈  V  | 
						
						
							| 8 | 
							
								
							 | 
							eleq1 | 
							⊢ ( 𝑗  =  𝐽  →  ( 𝑗  ∈  dom  𝐺  ↔  𝐽  ∈  dom  𝐺 ) )  | 
						
						
							| 9 | 
							
								8
							 | 
							anbi2d | 
							⊢ ( 𝑗  =  𝐽  →  ( ( 𝐺  ∈  𝐵  ∧  𝑗  ∈  dom  𝐺 )  ↔  ( 𝐺  ∈  𝐵  ∧  𝐽  ∈  dom  𝐺 ) ) )  | 
						
						
							| 10 | 
							
								
							 | 
							fveq2 | 
							⊢ ( 𝑗  =  𝐽  →  ( 𝐺 ‘ 𝑗 )  =  ( 𝐺 ‘ 𝐽 ) )  | 
						
						
							| 11 | 
							
								10
							 | 
							sseq1d | 
							⊢ ( 𝑗  =  𝐽  →  ( ( 𝐺 ‘ 𝑗 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  ↔  ( 𝐺 ‘ 𝐽 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 12 | 
							
								9 11
							 | 
							imbi12d | 
							⊢ ( 𝑗  =  𝐽  →  ( ( ( 𝐺  ∈  𝐵  ∧  𝑗  ∈  dom  𝐺 )  →  ( 𝐺 ‘ 𝑗 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  ↔  ( ( 𝐺  ∈  𝐵  ∧  𝐽  ∈  dom  𝐺 )  →  ( 𝐺 ‘ 𝐽 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) ) ) )  | 
						
						
							| 13 | 
							
								5
							 | 
							elexi | 
							⊢ 𝐺  ∈  V  | 
						
						
							| 14 | 
							
								
							 | 
							eleq1 | 
							⊢ ( 𝑔  =  𝐺  →  ( 𝑔  ∈  𝐵  ↔  𝐺  ∈  𝐵 ) )  | 
						
						
							| 15 | 
							
								
							 | 
							dmeq | 
							⊢ ( 𝑔  =  𝐺  →  dom  𝑔  =  dom  𝐺 )  | 
						
						
							| 16 | 
							
								15
							 | 
							eleq2d | 
							⊢ ( 𝑔  =  𝐺  →  ( 𝑗  ∈  dom  𝑔  ↔  𝑗  ∈  dom  𝐺 ) )  | 
						
						
							| 17 | 
							
								14 16
							 | 
							anbi12d | 
							⊢ ( 𝑔  =  𝐺  →  ( ( 𝑔  ∈  𝐵  ∧  𝑗  ∈  dom  𝑔 )  ↔  ( 𝐺  ∈  𝐵  ∧  𝑗  ∈  dom  𝐺 ) ) )  | 
						
						
							| 18 | 
							
								
							 | 
							fveq1 | 
							⊢ ( 𝑔  =  𝐺  →  ( 𝑔 ‘ 𝑗 )  =  ( 𝐺 ‘ 𝑗 ) )  | 
						
						
							| 19 | 
							
								18
							 | 
							sseq1d | 
							⊢ ( 𝑔  =  𝐺  →  ( ( 𝑔 ‘ 𝑗 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  ↔  ( 𝐺 ‘ 𝑗 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 20 | 
							
								17 19
							 | 
							imbi12d | 
							⊢ ( 𝑔  =  𝐺  →  ( ( ( 𝑔  ∈  𝐵  ∧  𝑗  ∈  dom  𝑔 )  →  ( 𝑔 ‘ 𝑗 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  ↔  ( ( 𝐺  ∈  𝐵  ∧  𝑗  ∈  dom  𝐺 )  →  ( 𝐺 ‘ 𝑗 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) ) ) )  | 
						
						
							| 21 | 
							
								1 2 3 4
							 | 
							bnj1014 | 
							⊢ ( ( 𝑔  ∈  𝐵  ∧  𝑗  ∈  dom  𝑔 )  →  ( 𝑔 ‘ 𝑗 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 22 | 
							
								13 20 21
							 | 
							vtocl | 
							⊢ ( ( 𝐺  ∈  𝐵  ∧  𝑗  ∈  dom  𝐺 )  →  ( 𝐺 ‘ 𝑗 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 23 | 
							
								7 12 22
							 | 
							vtocl | 
							⊢ ( ( 𝐺  ∈  𝐵  ∧  𝐽  ∈  dom  𝐺 )  →  ( 𝐺 ‘ 𝐽 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  |