Metamath Proof Explorer


Theorem nfse

Description: Bound-variable hypothesis builder for set-like relations. (Contributed by Mario Carneiro, 24-Jun-2015) (Revised by Mario Carneiro, 14-Oct-2016)

Ref Expression
Hypotheses nffr.r _xR
nffr.a _xA
Assertion nfse xRSeA

Proof

Step Hyp Ref Expression
1 nffr.r _xR
2 nffr.a _xA
3 df-se RSeAbAaA|aRbV
4 nfcv _xa
5 nfcv _xb
6 4 1 5 nfbr xaRb
7 6 2 nfrabw _xaA|aRb
8 7 nfel1 xaA|aRbV
9 2 8 nfralw xbAaA|aRbV
10 3 9 nfxfr xRSeA