| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dvhopsp.s |  |-  S = ( s e. E , f e. ( T X. E ) |-> <. ( s ` ( 1st ` f ) ) , ( s o. ( 2nd ` f ) ) >. ) | 
						
							| 2 |  | opelxpi |  |-  ( ( F e. T /\ U e. E ) -> <. F , U >. e. ( T X. E ) ) | 
						
							| 3 | 1 | dvhvscaval |  |-  ( ( R e. E /\ <. F , U >. e. ( T X. E ) ) -> ( R S <. F , U >. ) = <. ( R ` ( 1st ` <. F , U >. ) ) , ( R o. ( 2nd ` <. F , U >. ) ) >. ) | 
						
							| 4 | 2 3 | sylan2 |  |-  ( ( R e. E /\ ( F e. T /\ U e. E ) ) -> ( R S <. F , U >. ) = <. ( R ` ( 1st ` <. F , U >. ) ) , ( R o. ( 2nd ` <. F , U >. ) ) >. ) | 
						
							| 5 |  | op1stg |  |-  ( ( F e. T /\ U e. E ) -> ( 1st ` <. F , U >. ) = F ) | 
						
							| 6 | 5 | fveq2d |  |-  ( ( F e. T /\ U e. E ) -> ( R ` ( 1st ` <. F , U >. ) ) = ( R ` F ) ) | 
						
							| 7 |  | op2ndg |  |-  ( ( F e. T /\ U e. E ) -> ( 2nd ` <. F , U >. ) = U ) | 
						
							| 8 | 7 | coeq2d |  |-  ( ( F e. T /\ U e. E ) -> ( R o. ( 2nd ` <. F , U >. ) ) = ( R o. U ) ) | 
						
							| 9 | 6 8 | opeq12d |  |-  ( ( F e. T /\ U e. E ) -> <. ( R ` ( 1st ` <. F , U >. ) ) , ( R o. ( 2nd ` <. F , U >. ) ) >. = <. ( R ` F ) , ( R o. U ) >. ) | 
						
							| 10 | 9 | adantl |  |-  ( ( R e. E /\ ( F e. T /\ U e. E ) ) -> <. ( R ` ( 1st ` <. F , U >. ) ) , ( R o. ( 2nd ` <. F , U >. ) ) >. = <. ( R ` F ) , ( R o. U ) >. ) | 
						
							| 11 | 4 10 | eqtrd |  |-  ( ( R e. E /\ ( F e. T /\ U e. E ) ) -> ( R S <. F , U >. ) = <. ( R ` F ) , ( R o. U ) >. ) |