Validity rules need to be added to the ARCHETYPE_ONTOLOGY class so that they can be checked and reported by compilers.
Enhancement required in validator; no changes to parsers.
Add the following rules:
- VONLC - languages consistent: all term codes and constraint codes occur in all languages
- VONSD - term or constraint code defined in archetype ontology must be of the same specialisation level as the archetype (differential archetypes), or the same or a less specialised level (flat archetypes)