Bert Verhees wrote:
> ELEMENT[at0033] occurrences matches {0..1} matches { -- Condition
> Status
> value matches {
> DV_TEXT matches {*}
> }
> }
> ...
>
> Is it so that in an archetype-snippet like this, value is a required
> attribute?
According to the openEHR data structures specification, ELEMENT.value
is 0..1. It's optional, as long as a null flavour is supplied.
Invariants:
Is_null_valid: is_null = (value = Void)
Null_flavour_indicated: is_null xor null_flavour = Void
In other words, (value = Void) = not (null_flavour = Void). The
ELEMENT must have either a value, or a null flavour, but not both.
- Peter Gummer
