DTV13 — Unusual use of 'that' in definitions

OMG Specification: Date Time Vocabulary

Version: 1.0

Title: Unusual use of 'that' in definitions

Summary:

In clause 8.5, the Definition of ‘time scale’ reads:

“regular sequence that each member of the regular sequence is a time point”

I see nothing in SBVR Annex C that suggests a meaning for this. I would expect:

<more general concept> that <verb> <other roles>

where the ‘that’ is the subject (role 1) of the verb concept wording;

or

<more general concept> that <subject> <verb>

where the ‘that’ is the direct object (role 2) of the verb concept wording.

But in the given definition, the verb is ‘is’, the subject is ‘each member of the regular sequence’ and the direct object is ‘a time point’. What role does the ‘that’ play? How does this delimit ‘regular sequence’?

The intention is: “regular sequence such that each member of the regular sequence is a time point”

or: “regular sequence of which each member is a time point”

or: “regular sequence (all of) whose members are time points”

The first is a style that is conventional in mathematics, but perhaps not in business usage. It is not mentioned in SBVR Annex C, but neither of the others is, either. Is this an SBVR SE problem?

Note: there are several definitions in DTV with ‘that’ playing no clear role in the delimiting verb. This is just one example of the usage.

Defer for resolution of SBVR issue

The underlying issue is the apparent limitations on the expressiveness of SBVR Structured English. All of the "misuses" of 'that' could be replaced by 'such that', if it were permissible in SBVR SE. Many could be rephrased for business users by permitting qualifier clauses that begin "of which" or "the <noun form> of which" or "whose <noun form>". A corresponding issue has been raised to the SBVR RTF. This issue is Deferred until that issue is resolved.