Metamath Proof Explorer


Theorem nfrn

Description: Bound-variable hypothesis builder for range. (Contributed by NM, 1-Sep-1999) (Revised by Mario Carneiro, 15-Oct-2016)

Ref Expression
Hypothesis nfrn.1 _xA
Assertion nfrn _xranA

Proof

Step Hyp Ref Expression
1 nfrn.1 _xA
2 df-rn ranA=domA-1
3 1 nfcnv _xA-1
4 3 nfdm _xdomA-1
5 2 4 nfcxfr _xranA