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What does the "or" symbol mean as in the following post:

How to prove $\gcd(a,\gcd(b, c)) = \gcd(\gcd(a, b), c)$?

In particular, the symbol is used in the above linked post in the following definition of $\gcd(a, b)$:

Given integers $a$ and $b$, there is one and only one number $d$ with the following properties.

  1. $d \geq 0$
  2. $d\mid a$ and $d\mid b$
  3. $e\mid a$ and $e\mid b$ implies $e\mid d$.
  • It is not an "or" symbol, it is a vertical bar. Saying it is an "or" symbol is already applying a (here inappropriate) interpretation to it. – Marc van Leeuwen Dec 10 '14 at 11:08

2 Answers2

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you mean $d|a$. It is not 'or' symbol. It means d divides a.

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In this context, you write $a|b$ to mean that $a$ divides $b$, or equivalently, that there is an integer $m$ such that $b=ma$.

See the article Divisor on Wikipedia, and also Vertical bar for other uses of this symbol.