Category: News

What are natural numbers?

What are the natural numbers? Is it a valid question at all? My understanding is that a set satisfying Peano axioms is called "the natural numbers" and fr...

Prove B is a proper subset of A

Let $A=\{m \in \mathbb{Z} \mid m=4 a+3$ for some integer $a\}$ and let $B=\{n \in \mathbb{Z} \mid n=12 b+7$ for some integer $b\}$. Prove that $B \subset ...