Metamath Proof Explorer


Theorem nfitg

Description: Bound-variable hypothesis builder for an integral: if y is (effectively) not free in A and B , it is not free in S. A B _d x . (Contributed by Mario Carneiro, 28-Jun-2014)

Ref Expression
Hypotheses nfitg.1 _yA
nfitg.2 _yB
Assertion nfitg _yABdx

Proof

Step Hyp Ref Expression
1 nfitg.1 _yA
2 nfitg.2 _yB
3 eqid Bik=Bik
4 3 dfitg ABdx=k=03ik2xifxA0BikBik0
5 nfcv _y03
6 nfcv _yik
7 nfcv _y×
8 nfcv _y2
9 nfcv _y
10 1 nfcri yxA
11 nfcv _y0
12 nfcv _y
13 nfcv _y
14 nfcv _y÷
15 2 14 6 nfov _yBik
16 13 15 nffv _yBik
17 11 12 16 nfbr y0Bik
18 10 17 nfan yxA0Bik
19 18 16 11 nfif _yifxA0BikBik0
20 9 19 nfmpt _yxifxA0BikBik0
21 8 20 nffv _y2xifxA0BikBik0
22 6 7 21 nfov _yik2xifxA0BikBik0
23 5 22 nfsum _yk=03ik2xifxA0BikBik0
24 4 23 nfcxfr _yABdx