Metamath Proof Explorer


Theorem nfofr

Description: Hypothesis builder for function relation. (Contributed by Mario Carneiro, 28-Jul-2014)

Ref Expression
Hypothesis nfof.1
|- F/_ x R
Assertion nfofr
|- F/_ x oR R

Proof

Step Hyp Ref Expression
1 nfof.1
 |-  F/_ x R
2 df-ofr
 |-  oR R = { <. u , v >. | A. w e. ( dom u i^i dom v ) ( u ` w ) R ( v ` w ) }
3 nfcv
 |-  F/_ x ( dom u i^i dom v )
4 nfcv
 |-  F/_ x ( u ` w )
5 nfcv
 |-  F/_ x ( v ` w )
6 4 1 5 nfbr
 |-  F/ x ( u ` w ) R ( v ` w )
7 3 6 nfralw
 |-  F/ x A. w e. ( dom u i^i dom v ) ( u ` w ) R ( v ` w )
8 7 nfopab
 |-  F/_ x { <. u , v >. | A. w e. ( dom u i^i dom v ) ( u ` w ) R ( v ` w ) }
9 2 8 nfcxfr
 |-  F/_ x oR R