Better Use of RDF Inferencing

[twalmsley]

Improve the mapping of HQDM to RDF. This mapping is currently ad-hoc and there may be ways to improve it. This task will investigate the options and propose a way forward, assessing the impact on existing code and models.

• Make instances of kind_of_X into rdfs:subClassOf X. (See rule below) See Kinds as rdfs:subClassOf #198
• Use of RDFS inference rules along with the HQDM RDF schema makes the HQDM data models richer and easier to query in general ways. For example, without inference rules, querying for entities of type party will not return person or organization entities, but they are returned when inference rules are used.
• Some additional HQDM-specific inference rules will be useful, e.g.:
  • If A member_of_kind B then A rdf:type B
  • If A rdf:type B and B rdf:type hqdm:class then A member_of_kind B
  • If A rdf:type kind_of_X then A rdfs:subClassOf X (needs a rule instance for each kind_of_X)
  • If A rdfs:subClassOf X then A rdf:type kind_of_X (also needs a rule instance for each kind_of_X).
  • If A rdfs:subClassOf B then A has_superclass B.
  • If A has_superclass B then A rdfs:subClassOf B.
  • Similar pairs of rules for aggregation, composition, and temporal_composition.
  • If spatio_temporal_extent S is part_of_possible_world P then parts of S are part_of_possible_world P.
  • If A member_of B then B rdf:type rdfs:Class.
  • If C is a classification of A as a member of B then A member_of B.
  • If A member_of B then ∃C: C is a classification of A as a member of B.
  • If A has_superclass B then ∃S: S is a specialization such that A specialises B
  • If S is a specialization such that A specialises B then A has_superclass B.

The main purpose of these rules is to unify the two different extension mechanisms provided for extending HQDM - sub-typing and by creating 'kinds'. In theory if these rules are used then one form of extension mechanism can be inferred from the other.

[twalmsley]

As mentioned by @Fabalab and @GCHQDeveloper42 we should consider rules for inferring state_of_x and class_of_x types.