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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