Integers are central to the discrete mathematics we are emphasizing in this book. Therefore we want to explore the theory of numbers, an important branch of mathematics concerned with the properties of integers.
We tested the number theory waters in the previous chapter, by introducing binary operations called ‘mod’ and ‘gcd’. Now let’s plunge in and really immerse ourselves in the subject.
In other words, be prepared to drown.
4.1 Divisibility
We say that m divides n (or n is divisible by m) if m > 0 and the ratio n/m is an integer. This property underlies all of number theory, so it’s convenient to have a special notation for it. We therefore write
(The notation ‘m|n’ is actually much more common than ‘m\n’ in current mathematics ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month, and much more.
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
