Metamath Proof Explorer


Theorem negex

Description: A negative is a set. (Contributed by NM, 4-Apr-2005)

Ref Expression
Assertion negex - 𝐴 ∈ V

Proof

Step Hyp Ref Expression
1 df-neg - 𝐴 = ( 0 − 𝐴 )
2 1 ovexi - 𝐴 ∈ V