D Recurrences

[Andrej Mitrovic]

On 6/9/11, Steven Schveighoffer <schveiguy at yahoo.com> wrote:
> On Thu, 09 Jun 2011 14:45:49 -0400, Andrej Mitrovic
> <andrej.mitrovich at gmail.com> wrote:
>
>> I never understood why it's called "open" interval. What does it 'open'?
>
> Look at the terminology section of
> http://en.wikipedia.org/wiki/Interval_(mathematics)
>
> No clue as to the "why" :)
>
> -Steve
>

The why is what I'm after.

Let me take a look at some definitions of "open" from
thefreedictionary (excluding the definitions under the math section):
"Carried on in full view"
"Spread out; unfolded"
"Accessible to all"
"Lacking effective regulation"

It seems more natural to me to think of open as something that
encompasses a larger scope. E.g. when you spread your arms you have a
larger area between your hands, not smaller.