Multiple Delay alternatives : what it is useful to ?

["Hibou57 (Yannick Duchêne)" <yannick_duchene@yahoo.fr>]

Hi all out there,

[ARM 9.7.1(10)] and [ARM 9.7.1(13)],
http://www.adaic.org/standards/05rm/html/RM-9-7-1.html
explicitly allows multiple Delay alternatives in a Select statement
(finally GNAT was right), as I've checked.

Know I now it is legal, I just wonder why ?

If some delays stand for a time which is sooner than others delays
alternatives, the others will never be triggered. Or they may be ?
Does it have something to deal with variable delay ? If it is, the
runtime will then simply select the sooner ignoring all others ?

And what if two delays stands for the same time ? I do not see
anything which clarify this situation in the RM (may be I've missed
it).

Are they some real life examples of useful multiple delays
alternatives ?

By the way, a sentence is unclear to me : at 9.7.1(10), there is a “
If a selective_accept contains more than one delay_alternative, then
all shall be delay_relative_statements, or all shall be
delay_until_statements for the same time type. ” .... same time type ?
I could not construe these last three words.