# A question about the names of the components of an interval

Suppose you have the interval $[n,10n]$. How do you call the $n$ in this interval? I think the $n$ can be called the "independent variable of the interval" (since the interval $[n,10n]$ can be written as $[n,f(n)]$, where $f(n)=10n$), but I'm not sure.

• @grantfgates Suppose in the interval $[n,10n]$ you can replace $n$ with any positive integer. My question is: how do you call the $n$ in this interval? May 11 '14 at 19:31
• @grantfgates Example: "There is always a prime number in the interval $[n,10n]$, where $n$ can be any positive integer". I need to know another way of saying this. For example: "There is always a prime number in the interval $[n,10n]$, where the ... can be any positive integer". What can I replace "..." with? "Independent variable"? "Input"? Other words or expressions? May 13 '14 at 19:09