An unsophisticated question from a neophyte:
Given the numbers: $1,2,3,4,5$
What is the symbol for the range of the numbers?
i.e. the lowest-highest number in the set. For example, the min max is $1-5$.
The ____ is $1-5$. (insert math symbol into blank).
Should such a beast exist, I'd be particularly interested in it's unicode character...
Tried searching a few online resources, such as: without success.
$\endgroup$ 23 Answers
$\begingroup$You are looking for either:
A closed interval: $[a,b]$ represents the set of all real numbers greater or equal to $a$ and less or equal to $b$.
A integer interval: $[a\ldotp\ldotp b]$ represents all integers in between $a$ and $b$. ($[1\ldotp\ldotp 5] = \{1,2,3,4,5\}$)
This is a useful wikipedia reference.
It is important to make the distinction between whether or not a particular endpoint is included. Use ( or ) to exclude and [ or ] to include.
For instance
$$(a,b) \;\;\Rightarrow \;\; \{x\in\Bbb R:a<x<b\}$$ $$[a,b] \;\;\Rightarrow \;\;\{x\in\Bbb R:a\le x\le b\}$$ $$\{a..b\} \;\;\Rightarrow \;\;\{x\in\Bbb Z:a\le x\le b\}$$
$\endgroup$ 2 $\begingroup$I would like to add to Henricus answer as it gives the answer for a integer range but not for ranges of general step sizes, which is something that is very common in programming.
The expression
$$\{s k \mid k \in [a..b] \}$$would give you a range from $sa$ to $sb$ with increments of s.
So if you wanted to write an expression for the numbers $$\{-3,-2.5, -2, -1.5, -1, -0.5, 0, 0.5, 1, 1.5, 2, 2.5, 3\}$$that could be written as $$\{\frac{1}{2} k \mid k \in [-6..6] \}.$$
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