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 _ x A
Assertion nfrn _ x ran A

Proof

Step Hyp Ref Expression
1 nfrn.1 _ x A
2 df-rn ran A = dom A -1
3 1 nfcnv _ x A -1
4 3 nfdm _ x dom A -1
5 2 4 nfcxfr _ x ran A