DV_DURATION as ranges

As Ian suggested I copy this issue from CKM to the technical list.
I have seen that in some archetypes (e.g. Apgar or BloodPressure) that
use DV_Duration restrictions (such as the width of the interval event
in the blood pressure archetype or the famous offset in the apgar
archetype) define them like this:

offset existence matches {1..1} matches {
                            DV_DURATION[at0040] occurrences matches
{0..1} matches { --
                                value existence matches {1..1} matches {|PT10M|}
                            }
                        }

As you can see, even if it is a single default value (10 minutes),
they are defined as ranges. As durations allow the definition of
default values (and they parse correctly) I think they should be
changed to this:

offset existence matches {1..1} matches {
                            DV_DURATION[at0040] occurrences matches
{0..1} matches { --
                                value existence matches {1..1} matches {PT10M}
                            }
                        }

As checking a concrete value is always easier than a range I would
suggest to change them to that.

No comments about this one?

I thought I had replied to this, but must not have. Anyway, I don't
understand why single point values are not used either, rather than
point ranges (which seem somewhat pointless :wink:

- thomas

Hi Tom and Diego,
The reference workbench only has an interval constraint on duration as it is
the logical constraint. If this is a point duration then it still expresses
a range. Not sure if this has changed over time.
Cheers, Sam