Metamath Proof Explorer


Theorem nfesum1

Description: Bound-variable hypothesis builder for extended sum. (Contributed by Thierry Arnoux, 19-Oct-2017)

Ref Expression
Hypothesis nfesum1.1
|- F/_ k A
Assertion nfesum1
|- F/_ k sum* k e. A B

Proof

Step Hyp Ref Expression
1 nfesum1.1
 |-  F/_ k A
2 df-esum
 |-  sum* k e. A B = U. ( ( RR*s |`s ( 0 [,] +oo ) ) tsums ( k e. A |-> B ) )
3 nfcv
 |-  F/_ k ( RR*s |`s ( 0 [,] +oo ) )
4 nfcv
 |-  F/_ k tsums
5 nfmpt1
 |-  F/_ k ( k e. A |-> B )
6 3 4 5 nfov
 |-  F/_ k ( ( RR*s |`s ( 0 [,] +oo ) ) tsums ( k e. A |-> B ) )
7 6 nfuni
 |-  F/_ k U. ( ( RR*s |`s ( 0 [,] +oo ) ) tsums ( k e. A |-> B ) )
8 2 7 nfcxfr
 |-  F/_ k sum* k e. A B