Interop fidelity contract

Documentation status: reference.

Interop is not described as a vague promise of portability. For each concept crossing an external representation boundary, classify the mapping.

Classification	Meaning
Preserved	Identity and semantics survive without structural change.
Reified	A higher-arity/contextual construct is represented explicitly as an object/structure in the target model.
Projected	Only a declared view/subset is exported; information loss is intentional and documented.
Not represented	The target representation has no supported mapping; the loss is explicit.

Round-trip rule

When a mapping is claimed to be reversible, test a round trip against the conceptual contract rather than comparing serialized text. XML and YAML, for example, are equivalent when they produce the same relevant declarative DOM/contract, not because their source text resembles each other.

Binding rule

Generated host-language bindings are projections of the published Runtime contract. They must not feed host-language implementation vocabulary back into the ontology merely because one operationalization uses that language.

This contract is the technical answer to lock-in: losses and transformations are named, testable and versionable.