Unfamiliar use of interval brackets

Hey, I was wondering if anyone could clear up for me what would generally be meant when you say that a certain value has to

"lie within the strip ] x , y ["? What exactly does it signify when the brackets are in the opposite direction as compared to how you would indicate a closed interval from x to y, [x,y]?

Re: Unfamiliar use of interval brackets

Quote:

Originally Posted by

**Scurmicurv** Hey, I was wondering if anyone could clear up for me what would generally be meant when you say that a certain value has to

"lie within the strip ] x , y ["? What exactly does it signify when the brackets are in the opposite direction as compared to how you would indicate a closed interval from x to y, [x,y]?

That notation is unusual but not unheard of.

$\displaystyle ]a,b[=\{x: a<x<b\}=(a,b)$,

$\displaystyle ]a,b]=\{x: a<x\le b\}=(a,b]$ ,

etc.

Re: Unfamiliar use of interval brackets

Aha, so it's just an open interval? Thanks, that helps a lot to get that cleared up!