Metamath Proof Explorer


Theorem nfneg

Description: Bound-variable hypothesis builder for the negative of a complex number. (Contributed by NM, 12-Jun-2005) (Revised by Mario Carneiro, 15-Oct-2016)

Ref Expression
Hypothesis nfneg.1
|- F/_ x A
Assertion nfneg
|- F/_ x -u A

Proof

Step Hyp Ref Expression
1 nfneg.1
 |-  F/_ x A
2 1 a1i
 |-  ( T. -> F/_ x A )
3 2 nfnegd
 |-  ( T. -> F/_ x -u A )
4 3 mptru
 |-  F/_ x -u A