Given two closed intervals M, N what is the definition of M - N?

53 Views Asked by At

I'm reading a math book that goes from elementary math concepts to more advanced concepts taught in college. I understand that M - N should be equal to a set containing elements in M that are not in N.

In this book, there is a question which is the same as the title of this one. I don't understand the result.

Where:

M = [2; 6]

N = [4; 8[

[2;4] includes 4 in the range, which is also included in [4;8]

So M-N is including 4 which is also present in N. What am I missing?

1

There are 1 best solutions below

1
On BEST ANSWER

Yes, the set difference $[2,6]\setminus [4,8)$ is $[2,4)$ -- or $[2,4[$ in French/German notation.

If you have a book that claims it is $[2,4]$, it is either a typo, or the minus in $M-N$ means something different from $M\setminus N$.