Abbreviations & Definitions

To avoid redundancies I put some of the more often used abbreviations and the, mostly mathematical, definitions here.
(This blogging software does some weird things to the former definition list here, my…)


The set of natural numbers according to Zermelo–Fraenkel (ZF) set theory:
Define 0 = \{\} and n+1=n\cup\{n\} to construct finite sets whose cardinalities build the set of the naturals numbers \mathbb{N}.
tl;dr: \mathbb{N} = \{0,1,2,3,\cdots\}


\mathbb{N}^+ = \mathbb{N}\setminus\{0\}


\mathbb{Z} = \{n,-n|n\in\mathbb{N}\}


\mathbb{Z}^* = \mathbb{N}


\mathbb{Z}^* = \mathbb{N}^+


\mathbb{Z}/n is the set of integers modulo n


\mathbb{P} is the set of primes


\infty is not a number. Nevertheless it gets used here in limits like \lim_{x\to 0}\tfrac{1}{x}=\infty or \sum_{n=1}\tfrac{1}{n}. It is invisible in the latter example. Twice.


is the set of infinite integers. Not used here.

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