Metamath Proof Explorer


Theorem opprdrng

Description: The opposite of a division ring is also a division ring. (Contributed by NM, 18-Oct-2014)

Ref Expression
Hypothesis opprdrng.1 O = opp r R
Assertion opprdrng R DivRing O DivRing

Proof

Step Hyp Ref Expression
1 opprdrng.1 O = opp r R
2 1 opprringb R Ring O Ring
3 2 anbi1i R Ring Unit R = Base R 0 R O Ring Unit R = Base R 0 R
4 eqid Base R = Base R
5 eqid Unit R = Unit R
6 eqid 0 R = 0 R
7 4 5 6 isdrng R DivRing R Ring Unit R = Base R 0 R
8 1 4 opprbas Base R = Base O
9 5 1 opprunit Unit R = Unit O
10 1 6 oppr0 0 R = 0 O
11 8 9 10 isdrng O DivRing O Ring Unit R = Base R 0 R
12 3 7 11 3bitr4i R DivRing O DivRing