Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

R is the set of real numbers.

Z is the set of integers {.., -2, -1, 0, 1, 2, ...}.

Z is called "Z" due to influential German mathematicians who chose the letter to stand for "zahlen" ("number" in German).

As a fun fact, the letter "N" stands for "natural numbers," meaning either positive integers, or positive integers and zero. However, that letter (N) is _not_ standardized because mathematicians disagree about whether or not to include zero. When I separately told a couple of my professors this in grad school, they didn't believe me — one of them thinking it was crazy for zero to be excluded, the other thinking it was crazy to include it!

https://en.wikipedia.org/wiki/Natural_number



Thank you!




Consider applying for YC's Summer 2026 batch! Applications are open till May 4

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: