Edward C. Zimmermann wrote:

> We have time intervals (5.5) and Recurring time-intervals (5.6)

Thanks. At "4.1 Basic concepts" the specification says "three concepts 
are fundamental:" to list four concepts afterwards. :-) I'll skipp 
recurring time-intervals for simplicity. So there is (citing the 

1. Time-point: instant in the laps of time regarded as dimensionless

Examples of simple time-points are dates.

2. Time-interval: a portion of time between two time-points.

A time-interval is one of
- a start and an end
- a duration not associated with any start or end
- a start and a duration
- a duration and an end

As I read the specification, a "start" or "end" is an instance of a 
time-point. Time intervals and Time points can be compared by the method 
"inside of".

We now extend this model by introducing:

3. Time-collection: a set of time-points and/or time-intervals.

4. Time-choice: One of
- a time-collection, that one unknown element is selected from
- a time-interval, that one unknown time-interval or time-point is 
selected from

5. Approximate times: A time-point, time-interval, or time-collection 
marked as approximate.

6. Questionable times: A time-point, time-interval, time-collection, or 
approximate time marked as approximate.


Jakob Vo▀ <[log in to unmask]>, skype: nichtich
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