SMM12 — Relax constraint requiring both boundary points of an Interval.

An interval with neither boundary specified ranges over the entire number line and provides no useful information to its RankingMeasure (and to its GradeMeasure when no gradeTo is specified). But the current constraint is too restrictive in that it requires both boundaries if either is specified. A better constraint would be requiring at least one boundary (but the second is optional).

The interval boundary properties are described as "endpoints" which is a term used elsewhere in the specification to mean the ends of "from" and "to" association. Describing the minimum and maximum properties of the intervals as boundaries would remove any possible confusion with respect to "endpoint" .

Also, the boundaries are misidentified in Figure 10.2 and in the semantics clauses of 13.7 and 13.9 as minimumEndPoint and maximumEndPoint. Figure 10.2 is even inconsistent with the definition of the attributes in the Attributes table of Sub-clause 10.15. The semantics clauses of 13.7 and 13.9 contain sentences which start with "A numeric value is in the interval if and only if the it ". "the it" typo needs to be replaced with a reference back to the numeric value.

Relax constraint requiring both boundary points of an Interval

Loosen constraint to require only one end point, but not both. Use proper terminology for boundaries of intervals.