Metamath Proof Explorer


Theorem opprnzr

Description: The opposite of a nonzero ring is nonzero. (Contributed by Mario Carneiro, 17-Jun-2015)

Ref Expression
Hypothesis opprnzr.1 ⊢ O = opp r ⁡ R
Assertion opprnzr ⊢ R ∈ NzRing → O ∈ NzRing

Proof

Step Hyp Ref Expression
1 opprnzr.1 ⊢ O = opp r ⁡ R
2 1 opprnzrb ⊢ R ∈ NzRing ↔ O ∈ NzRing
3 2 biimpi ⊢ R ∈ NzRing → O ∈ NzRing