Prove-a-non-empty-set-S-of-a-group-G-wrt-binary-operation-is-a-sub-group-of-G-Iff-1-a-b-S-a-b-S-2-a-S-a-1-S-Hello-

Question Number 192095 by Mastermind last updated on 07/May/23

Prove a non - empty set S of a group

G wrt binary operation * is a sub -

group of G . Iff

1) a, b \in S \Rightarrow a * b \in S

2) a \in S \Rightarrow a^{- 1} \in S .

Hello