Theorem $:$ Every finite abelian $p$-group is the direct product of cyclic groups.
I have started reading that proof from this Proof Wiki article. Here I have understood everything before the element $b$ is introduced. Actually I can't understand what's the definition of $b$ mentioned in this article. Can anybody please make it clear to me?
Thanks for your valuable time.
Best Answer
We need only to take any element $b \in G \setminus \left \langle a \right \rangle$ which has the minimal order amongst all the elements of $G \setminus \left \langle a \right \rangle.$ Then it will have the required property as mentioned in the article of the link.