Metamath Proof Explorer


Definition df-2idl

Description: Define the class of two-sided ideals of a ring. A two-sided ideal is a left ideal which is also a right ideal (or a left ideal over the opposite ring). (Contributed by Mario Carneiro, 14-Jun-2015)

Ref Expression
Assertion df-2idl 2Ideal = r V LIdeal r LIdeal opp r r

Detailed syntax breakdown

Step Hyp Ref Expression
0 c2idl class 2Ideal
1 vr setvar r
2 cvv class V
3 clidl class LIdeal
4 1 cv setvar r
5 4 3 cfv class LIdeal r
6 coppr class opp r
7 4 6 cfv class opp r r
8 7 3 cfv class LIdeal opp r r
9 5 8 cin class LIdeal r LIdeal opp r r
10 1 2 9 cmpt class r V LIdeal r LIdeal opp r r
11 0 10 wceq wff 2Ideal = r V LIdeal r LIdeal opp r r