Metamath Proof Explorer


Definition df-simpg

Description: Define class of all simple groups. A simple group is a group ( df-grp ) with exactly two normal subgroups. These are always the subgroup of all elements and the subgroup containing only the identity ( simpgnsgbid ). (Contributed by Rohan Ridenour, 3-Aug-2023)

Ref Expression
Assertion df-simpg ⊢ SimpGrp = g ∈ Grp | NrmSGrp ⁡ g ≈ 2 𝑜

Detailed syntax breakdown

Step Hyp Ref Expression
0 csimpg class SimpGrp
1 vg setvar g
2 cgrp class Grp
3 cnsg class NrmSGrp
4 1 cv setvar g
5 4 3 cfv class NrmSGrp ⁡ g
6 cen class ≈
7 c2o class 2 𝑜
8 5 7 6 wbr wff NrmSGrp ⁡ g ≈ 2 𝑜
9 8 1 2 crab class g ∈ Grp | NrmSGrp ⁡ g ≈ 2 𝑜
10 0 9 wceq wff SimpGrp = g ∈ Grp | NrmSGrp ⁡ g ≈ 2 𝑜