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 _ x R
nffr.a _ x A
Assertion nfse x R Se A

Proof

Step Hyp Ref Expression
1 nffr.r _ x R
2 nffr.a _ x A
3 df-se R Se A b A a A | a R b V
4 nfcv _ x a
5 nfcv _ x b
6 4 1 5 nfbr x a R b
7 6 2 nfrabw _ x a A | a R b
8 7 nfel1 x a A | a R b V
9 2 8 nfralw x b A a A | a R b V
10 3 9 nfxfr x R Se A