DMN15 — Improvement of Semantic Domains Specification

The definition of Semantic Domains / Types in 10.3.2 does not contain:

• a metamodel
• relationships between various types

I propose adding a metamodel and the following two relationship:

1. Conforms To
A semantic domain T1 conforms to a semantic domain T2 when an instance of T1 can be substituted at each place where an instance of T2 is expected.

2. Equivalent To
A semantic domain T1 is equivalent to a domain T2 iff they have the same name and the corresponding embedded semantic domains are equivalent. (e.g. List<Number> is equivalent only to List<Number> not List <String>).

The above relationships should be defined via tables, similar to the ones used to describe the semantics of logic operators (page 119 Table 38).

Resolved already

Resolved in an earlier version already when we introduced the type lattice.