Datatypes R2 Issue 106

IVL.any proposal

if you truly don't know any of low, high, or center, then you probably do not know the center. However, in some cases you want to say: "I don't know when it started nor when it ended, but I know at time t it was there. What to do about that? Gschadow 22:30, 11 January 2007 (CST)

use case

Don't know when something started, will end, or center, but you do know that it was happening at a given time.

This is common for observations (i.e. of disease processes), procedure, and scheduling.

Disposition

This was approved in INM, Atlanta 2007, Wed Q2.

Any is antithetical to low, high, width and center. It's possible to specify it with the other properties, but this is really confusing, so initially we will prohibit it's use with the other properties, and write the invariants accordingly.

operations

// defining any invariant(SET<T> s, T t) where s.any.equals(t) {

 s.contains(t);

} // any and overlap invariant(SET<T> r, SET<T> s) where r.contains(s.any) {

 r.intersection(s).isEmpty.not;

}