| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							bnj1413.1 | 
							⊢ 𝐵  =  (  pred ( 𝑋 ,  𝐴 ,  𝑅 )  ∪  ∪  𝑦  ∈   pred ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 2 | 
							
								
							 | 
							bnj1148 | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →   pred ( 𝑋 ,  𝐴 ,  𝑅 )  ∈  V )  | 
						
						
							| 3 | 
							
								
							 | 
							bnj893 | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  ∈  V )  | 
						
						
							| 4 | 
							
								
							 | 
							simp1 | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴  ∧  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  →  𝑅  FrSe  𝐴 )  | 
						
						
							| 5 | 
							
								
							 | 
							bnj1127 | 
							⊢ ( 𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  →  𝑦  ∈  𝐴 )  | 
						
						
							| 6 | 
							
								5
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴  ∧  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  →  𝑦  ∈  𝐴 )  | 
						
						
							| 7 | 
							
								
							 | 
							bnj893 | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑦  ∈  𝐴 )  →   trCl ( 𝑦 ,  𝐴 ,  𝑅 )  ∈  V )  | 
						
						
							| 8 | 
							
								4 6 7
							 | 
							syl2anc | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴  ∧  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  →   trCl ( 𝑦 ,  𝐴 ,  𝑅 )  ∈  V )  | 
						
						
							| 9 | 
							
								8
							 | 
							3expia | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →  ( 𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  →   trCl ( 𝑦 ,  𝐴 ,  𝑅 )  ∈  V ) )  | 
						
						
							| 10 | 
							
								9
							 | 
							ralrimiv | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →  ∀ 𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 )  ∈  V )  | 
						
						
							| 11 | 
							
								
							 | 
							iunexg | 
							⊢ ( (  trCl ( 𝑋 ,  𝐴 ,  𝑅 )  ∈  V  ∧  ∀ 𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 )  ∈  V )  →  ∪  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 )  ∈  V )  | 
						
						
							| 12 | 
							
								3 10 11
							 | 
							syl2anc | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →  ∪  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 )  ∈  V )  | 
						
						
							| 13 | 
							
								2 12
							 | 
							bnj1149 | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →  (  pred ( 𝑋 ,  𝐴 ,  𝑅 )  ∪  ∪  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 ) )  ∈  V )  | 
						
						
							| 14 | 
							
								
							 | 
							bnj906 | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →   pred ( 𝑋 ,  𝐴 ,  𝑅 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 15 | 
							
								
							 | 
							iunss1 | 
							⊢ (  pred ( 𝑋 ,  𝐴 ,  𝑅 )  ⊆   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  →  ∪  𝑦  ∈   pred ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 )  ⊆  ∪  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 ) )  | 
						
						
							| 16 | 
							
								
							 | 
							unss2 | 
							⊢ ( ∪  𝑦  ∈   pred ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 )  ⊆  ∪  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 )  →  (  pred ( 𝑋 ,  𝐴 ,  𝑅 )  ∪  ∪  𝑦  ∈   pred ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 ) )  ⊆  (  pred ( 𝑋 ,  𝐴 ,  𝑅 )  ∪  ∪  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 17 | 
							
								14 15 16
							 | 
							3syl | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →  (  pred ( 𝑋 ,  𝐴 ,  𝑅 )  ∪  ∪  𝑦  ∈   pred ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 ) )  ⊆  (  pred ( 𝑋 ,  𝐴 ,  𝑅 )  ∪  ∪  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 18 | 
							
								1 17
							 | 
							eqsstrid | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →  𝐵  ⊆  (  pred ( 𝑋 ,  𝐴 ,  𝑅 )  ∪  ∪  𝑦  ∈   trCl ( 𝑋 ,  𝐴 ,  𝑅 )  trCl ( 𝑦 ,  𝐴 ,  𝑅 ) ) )  | 
						
						
							| 19 | 
							
								13 18
							 | 
							ssexd | 
							⊢ ( ( 𝑅  FrSe  𝐴  ∧  𝑋  ∈  𝐴 )  →  𝐵  ∈  V )  |