| Step | Hyp | Ref | Expression | 
						
							| 1 |  | xporderlem.1 | ⊢ 𝑇  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( 𝐴  ×  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) )  ∧  ( ( 1st  ‘ 𝑥 ) 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 ) 𝑆 ( 2nd  ‘ 𝑦 ) ) ) ) } | 
						
							| 2 |  | df-br | ⊢ ( 〈 𝑎 ,  𝑏 〉 𝑇 〈 𝑐 ,  𝑑 〉  ↔  〈 〈 𝑎 ,  𝑏 〉 ,  〈 𝑐 ,  𝑑 〉 〉  ∈  𝑇 ) | 
						
							| 3 | 1 | eleq2i | ⊢ ( 〈 〈 𝑎 ,  𝑏 〉 ,  〈 𝑐 ,  𝑑 〉 〉  ∈  𝑇  ↔  〈 〈 𝑎 ,  𝑏 〉 ,  〈 𝑐 ,  𝑑 〉 〉  ∈  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( 𝐴  ×  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) )  ∧  ( ( 1st  ‘ 𝑥 ) 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 ) 𝑆 ( 2nd  ‘ 𝑦 ) ) ) ) } ) | 
						
							| 4 | 2 3 | bitri | ⊢ ( 〈 𝑎 ,  𝑏 〉 𝑇 〈 𝑐 ,  𝑑 〉  ↔  〈 〈 𝑎 ,  𝑏 〉 ,  〈 𝑐 ,  𝑑 〉 〉  ∈  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( 𝐴  ×  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) )  ∧  ( ( 1st  ‘ 𝑥 ) 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 ) 𝑆 ( 2nd  ‘ 𝑦 ) ) ) ) } ) | 
						
							| 5 |  | opex | ⊢ 〈 𝑎 ,  𝑏 〉  ∈  V | 
						
							| 6 |  | opex | ⊢ 〈 𝑐 ,  𝑑 〉  ∈  V | 
						
							| 7 |  | eleq1 | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( 𝑥  ∈  ( 𝐴  ×  𝐵 )  ↔  〈 𝑎 ,  𝑏 〉  ∈  ( 𝐴  ×  𝐵 ) ) ) | 
						
							| 8 |  | opelxp | ⊢ ( 〈 𝑎 ,  𝑏 〉  ∈  ( 𝐴  ×  𝐵 )  ↔  ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 ) ) | 
						
							| 9 | 7 8 | bitrdi | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( 𝑥  ∈  ( 𝐴  ×  𝐵 )  ↔  ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 ) ) ) | 
						
							| 10 | 9 | anbi1d | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( ( 𝑥  ∈  ( 𝐴  ×  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) )  ↔  ( ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) ) ) ) | 
						
							| 11 |  | vex | ⊢ 𝑎  ∈  V | 
						
							| 12 |  | vex | ⊢ 𝑏  ∈  V | 
						
							| 13 | 11 12 | op1std | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( 1st  ‘ 𝑥 )  =  𝑎 ) | 
						
							| 14 | 13 | breq1d | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( ( 1st  ‘ 𝑥 ) 𝑅 ( 1st  ‘ 𝑦 )  ↔  𝑎 𝑅 ( 1st  ‘ 𝑦 ) ) ) | 
						
							| 15 | 13 | eqeq1d | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ↔  𝑎  =  ( 1st  ‘ 𝑦 ) ) ) | 
						
							| 16 | 11 12 | op2ndd | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( 2nd  ‘ 𝑥 )  =  𝑏 ) | 
						
							| 17 | 16 | breq1d | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( ( 2nd  ‘ 𝑥 ) 𝑆 ( 2nd  ‘ 𝑦 )  ↔  𝑏 𝑆 ( 2nd  ‘ 𝑦 ) ) ) | 
						
							| 18 | 15 17 | anbi12d | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 ) 𝑆 ( 2nd  ‘ 𝑦 ) )  ↔  ( 𝑎  =  ( 1st  ‘ 𝑦 )  ∧  𝑏 𝑆 ( 2nd  ‘ 𝑦 ) ) ) ) | 
						
							| 19 | 14 18 | orbi12d | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( ( ( 1st  ‘ 𝑥 ) 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 ) 𝑆 ( 2nd  ‘ 𝑦 ) ) )  ↔  ( 𝑎 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( 𝑎  =  ( 1st  ‘ 𝑦 )  ∧  𝑏 𝑆 ( 2nd  ‘ 𝑦 ) ) ) ) ) | 
						
							| 20 | 10 19 | anbi12d | ⊢ ( 𝑥  =  〈 𝑎 ,  𝑏 〉  →  ( ( ( 𝑥  ∈  ( 𝐴  ×  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) )  ∧  ( ( 1st  ‘ 𝑥 ) 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 ) 𝑆 ( 2nd  ‘ 𝑦 ) ) ) )  ↔  ( ( ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) )  ∧  ( 𝑎 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( 𝑎  =  ( 1st  ‘ 𝑦 )  ∧  𝑏 𝑆 ( 2nd  ‘ 𝑦 ) ) ) ) ) ) | 
						
							| 21 |  | eleq1 | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( 𝑦  ∈  ( 𝐴  ×  𝐵 )  ↔  〈 𝑐 ,  𝑑 〉  ∈  ( 𝐴  ×  𝐵 ) ) ) | 
						
							| 22 |  | opelxp | ⊢ ( 〈 𝑐 ,  𝑑 〉  ∈  ( 𝐴  ×  𝐵 )  ↔  ( 𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐵 ) ) | 
						
							| 23 | 21 22 | bitrdi | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( 𝑦  ∈  ( 𝐴  ×  𝐵 )  ↔  ( 𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐵 ) ) ) | 
						
							| 24 | 23 | anbi2d | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( ( ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) )  ↔  ( ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 )  ∧  ( 𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐵 ) ) ) ) | 
						
							| 25 |  | vex | ⊢ 𝑐  ∈  V | 
						
							| 26 |  | vex | ⊢ 𝑑  ∈  V | 
						
							| 27 | 25 26 | op1std | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( 1st  ‘ 𝑦 )  =  𝑐 ) | 
						
							| 28 | 27 | breq2d | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( 𝑎 𝑅 ( 1st  ‘ 𝑦 )  ↔  𝑎 𝑅 𝑐 ) ) | 
						
							| 29 | 27 | eqeq2d | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( 𝑎  =  ( 1st  ‘ 𝑦 )  ↔  𝑎  =  𝑐 ) ) | 
						
							| 30 | 25 26 | op2ndd | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( 2nd  ‘ 𝑦 )  =  𝑑 ) | 
						
							| 31 | 30 | breq2d | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( 𝑏 𝑆 ( 2nd  ‘ 𝑦 )  ↔  𝑏 𝑆 𝑑 ) ) | 
						
							| 32 | 29 31 | anbi12d | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( ( 𝑎  =  ( 1st  ‘ 𝑦 )  ∧  𝑏 𝑆 ( 2nd  ‘ 𝑦 ) )  ↔  ( 𝑎  =  𝑐  ∧  𝑏 𝑆 𝑑 ) ) ) | 
						
							| 33 | 28 32 | orbi12d | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( ( 𝑎 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( 𝑎  =  ( 1st  ‘ 𝑦 )  ∧  𝑏 𝑆 ( 2nd  ‘ 𝑦 ) ) )  ↔  ( 𝑎 𝑅 𝑐  ∨  ( 𝑎  =  𝑐  ∧  𝑏 𝑆 𝑑 ) ) ) ) | 
						
							| 34 | 24 33 | anbi12d | ⊢ ( 𝑦  =  〈 𝑐 ,  𝑑 〉  →  ( ( ( ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) )  ∧  ( 𝑎 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( 𝑎  =  ( 1st  ‘ 𝑦 )  ∧  𝑏 𝑆 ( 2nd  ‘ 𝑦 ) ) ) )  ↔  ( ( ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 )  ∧  ( 𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐵 ) )  ∧  ( 𝑎 𝑅 𝑐  ∨  ( 𝑎  =  𝑐  ∧  𝑏 𝑆 𝑑 ) ) ) ) ) | 
						
							| 35 | 5 6 20 34 | opelopab | ⊢ ( 〈 〈 𝑎 ,  𝑏 〉 ,  〈 𝑐 ,  𝑑 〉 〉  ∈  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( 𝐴  ×  𝐵 )  ∧  𝑦  ∈  ( 𝐴  ×  𝐵 ) )  ∧  ( ( 1st  ‘ 𝑥 ) 𝑅 ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 ) 𝑆 ( 2nd  ‘ 𝑦 ) ) ) ) }  ↔  ( ( ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 )  ∧  ( 𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐵 ) )  ∧  ( 𝑎 𝑅 𝑐  ∨  ( 𝑎  =  𝑐  ∧  𝑏 𝑆 𝑑 ) ) ) ) | 
						
							| 36 |  | an4 | ⊢ ( ( ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 )  ∧  ( 𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐵 ) )  ↔  ( ( 𝑎  ∈  𝐴  ∧  𝑐  ∈  𝐴 )  ∧  ( 𝑏  ∈  𝐵  ∧  𝑑  ∈  𝐵 ) ) ) | 
						
							| 37 | 36 | anbi1i | ⊢ ( ( ( ( 𝑎  ∈  𝐴  ∧  𝑏  ∈  𝐵 )  ∧  ( 𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐵 ) )  ∧  ( 𝑎 𝑅 𝑐  ∨  ( 𝑎  =  𝑐  ∧  𝑏 𝑆 𝑑 ) ) )  ↔  ( ( ( 𝑎  ∈  𝐴  ∧  𝑐  ∈  𝐴 )  ∧  ( 𝑏  ∈  𝐵  ∧  𝑑  ∈  𝐵 ) )  ∧  ( 𝑎 𝑅 𝑐  ∨  ( 𝑎  =  𝑐  ∧  𝑏 𝑆 𝑑 ) ) ) ) | 
						
							| 38 | 4 35 37 | 3bitri | ⊢ ( 〈 𝑎 ,  𝑏 〉 𝑇 〈 𝑐 ,  𝑑 〉  ↔  ( ( ( 𝑎  ∈  𝐴  ∧  𝑐  ∈  𝐴 )  ∧  ( 𝑏  ∈  𝐵  ∧  𝑑  ∈  𝐵 ) )  ∧  ( 𝑎 𝑅 𝑐  ∨  ( 𝑎  =  𝑐  ∧  𝑏 𝑆 𝑑 ) ) ) ) |