| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-itg |  |-  S. A B _d x = sum_ k e. ( 0 ... 3 ) ( ( _i ^ k ) x. ( S.2 ` ( x e. RR |-> [_ ( Re ` ( B / ( _i ^ k ) ) ) / z ]_ if ( ( x e. A /\ 0 <_ z ) , z , 0 ) ) ) ) | 
						
							| 2 |  | nfcv |  |-  F/_ x ( 0 ... 3 ) | 
						
							| 3 |  | nfcv |  |-  F/_ x ( _i ^ k ) | 
						
							| 4 |  | nfcv |  |-  F/_ x x. | 
						
							| 5 |  | nfcv |  |-  F/_ x S.2 | 
						
							| 6 |  | nfmpt1 |  |-  F/_ x ( x e. RR |-> [_ ( Re ` ( B / ( _i ^ k ) ) ) / z ]_ if ( ( x e. A /\ 0 <_ z ) , z , 0 ) ) | 
						
							| 7 | 5 6 | nffv |  |-  F/_ x ( S.2 ` ( x e. RR |-> [_ ( Re ` ( B / ( _i ^ k ) ) ) / z ]_ if ( ( x e. A /\ 0 <_ z ) , z , 0 ) ) ) | 
						
							| 8 | 3 4 7 | nfov |  |-  F/_ x ( ( _i ^ k ) x. ( S.2 ` ( x e. RR |-> [_ ( Re ` ( B / ( _i ^ k ) ) ) / z ]_ if ( ( x e. A /\ 0 <_ z ) , z , 0 ) ) ) ) | 
						
							| 9 | 2 8 | nfsum |  |-  F/_ x sum_ k e. ( 0 ... 3 ) ( ( _i ^ k ) x. ( S.2 ` ( x e. RR |-> [_ ( Re ` ( B / ( _i ^ k ) ) ) / z ]_ if ( ( x e. A /\ 0 <_ z ) , z , 0 ) ) ) ) | 
						
							| 10 | 1 9 | nfcxfr |  |-  F/_ x S. A B _d x |