SBVR11 — SBVR Issue: Model expression structure

Title: Model expression structure
Specification: SBVR
Version: 1.0
Source: Ed Barkmeyer, NIST, edbark@nist.gov

Summary:

SBVR clause 8.2 defines 'starting character position' as a means of reference to a substring of a Text object. And the definition of placeholder in clause 8.3.4 treats the placeholder as a syntactic substring that is identified by its starting character position.
This is a junior programmer model of expressions – a poor PSM – and it doesn't work reliably for a number of surface languages.

The idea is that the unspecified representation of a concept may involve an expression that has a syntactic structure. Since SBVR has no idea what that syntactic structure is (because it belongs to an undefined surface language for which SBVR is the metamodel), it must define a general model of expressions sufficient to support the idea that a placeholder is a subexpression, and has a surface-language-defined means of identification.

Recommendation:

In 8.2, Delete 'starting character position'. Replace it with a model of expressions that makes clear the point at which surface-language grammar and orthography determine the technical structure of the expressions.

In 8.3.4, delete all references to 'starting character position' in the entry for 'placeholder', and replace them with references to the structural concepts (to be) defined in 8.2.

In 8.3.4, delete 'placeholder has starting character position' and replace it with a relationship to a structural concept (to be) defined in 8.2.

The issue is resolved by the resolution to Issue 13802, which adds a caveat to the section on fact type forms:
The elements defined here are intentionally minimal and may or may not be adequate for specific languages.
It is not intended that the scope of SBVR expand to include language structure.
Revised Text:
No change.
Disposition: Resolved