DTV — Date-Time Issue - Atomic Quantity Value Conversion

The final submission document recorded the following issue under the OCL Definition for "atomic quantity value1 is atomic quantity value2 converted to measurement unit":
Issue: These definitions are inadequate because they depend upon "quantity1 = quantity2" which is not defined. We need the concept "quantity value1 is equivalent to quantity value2".

Annex D.3.3 defines 'atomic quantity value' and 'compound quantity value', and related verb concepts, but (a) these are not defined in VIM; (b) arguably, they are out-of-scope for DTV; (c) although originally intended as the basis for 'atomic duration value' and 'compound duration value' in clause 9.1, they are barely mentioned in that clause; (d) some of the definitions in clause 9.1 have technical errors. Because of the nominal durations of the time units 'month' and 'year' Clause 9.1 goes further by also defining "precise" and "nominal" versions of each kind of 'duration value'. In effect, clause 9.1 completely redefines all aspects of duration values. The dependencies in clause 9.1. on Annex D.3.3 can be eliminated with very little change.

To simplify the specification, to fix some definitional errors, and to avoid concepts that may be out of scope, clause 9.1 concepts are adjusted to delete the dependencies on 'atomic quantity value' and 'compound quantity value', and the latter are dropped from Annex D.3.3.

• Fix the Definition of 'precise atomic duration value' in clause 9.1.2, which should define 'precise atomic duration value' as a kind of 'quantity value'.
• Fix the Definition of 'precise compound duration value' in clause 9.1.2 to show that it is a kind of 'compound duration value'.
• Fix the Definition of 'nominal atomic duration value' in clause 9.1.2 to show that it is a kind of 'atomic duration value', and correct a reference in a Note.
• Fix the Definition of 'nominal compound duration value' in clause 9.1.3, which should define 'nominal compound duration value' as a kind of 'compound duration value' rather than a kind of 'compound quantity value', and should say that it is composed of 'atomic duration values' rather than 'atomic quantity values'.
• Change a reference in table C.1 to 'atomic quantity value' to instead reference 'duration value'.
• Delete a note in an example in Annex C.2 that references 'compound quantity value'.
• Update a note in 'particular quantity' in Annex D.3.1 to remove a reference to 'compound quantity value'.
• Update the definition of 'quantity value' in Annex D.3.3 to use the definition from VIM.
• Update a Note in 'quantity value quantifies quantity' to remove a reference to 'atomic quantity value'.

Add 'quantity1 = quantity2", as a "See:" reference to SBVR's "thing1 is thing2".