Is there a mathematical term of an range where the start=end?

Question

If I was asking someone to define a range of numbers and they put the same number for the starting point as the ending point. Is there a mathematical term for this?

For example, a range of 1 to 1. (Essentially, just 1).

Also the closed interval $[1,1]$. – Mauro ALLEGRANZA Mar 22 '19 at 15:01 — Mauro ALLEGRANZA, Mar 22 '19 at 15:01

score 2 · Accepted Answer · answered Mar 22 '19 at 15:08

2

An interval $[a,a]$ is called a degenerate interval. See

answered Mar 22 '19 at 15:08

score 1 · Answer 2 · answered Mar 22 '19 at 15:02

It is a point, or more specifically a collection of numbers with only 1 element. Some ways to think about this is:

What does a number in the range $[a,a]$ look like? Well, it is a number $\geq a$ and $\leq a$, and the only number like that is $a$ itself

Is there a mathematical term of an range where the start=end?

2 Answers2