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 _ x A
Assertion nfneg _ x A


Step Hyp Ref Expression
1 nfneg.1 _ x A
2 1 a1i _ x A
3 2 nfnegd _ x A
4 3 mptru _ x A