ADR-A62: SPC Namespace Harmonisation and Integration Deferral

Status: Proposed Date: 2026-09-23 Related: Architecture Review §4.14, G-19, ontology-architecture.md, ADR-A01 Drafted by: Agent, autonomous session (P0.1.12). Pending human ratification — see phase-0-status.md. The namespace change itself has already been executed (see Consequences).

Context

SPC (ontology/spc/spec/spc.ttl, ~1227 lines; ontology/spc/README.md, ~1393 lines) is a fully specified, session-typed process calculus sitting unintegrated with the rest of LATTICE. It uses a placeholder namespace (http://example.org/spc#) instead of the shared nebularis.org base, and its projection/ directory is empty. ontology-architecture.md §3 previously stated only “integration is out of scope,” which reads as neglect rather than a stated sequencing decision.

Decision

Two coherent integration positions exist; this ADR picks one for now and names the other as future work, rather than leaving the choice implicit:

Position	Consequence	When
Integrate SPC as the orchestration substrate	Author `ontology/spc/projection/party.ttl` and `behaviour.ttl`; model every workflow as an SPC session type	Phase 4, gated on the runtime planes (ingestion, query, behaviour) being stable
Defer SPC, with the reason stated	Workflows remain conventional state machines in `C-02`/`C-06`/`C-10`; each workflow is documented in a uniform shape so a later SPC lift is mechanical	Phases 1–3, on the explicit condition that every workflow is documented uniformly (audited at the Phase 3 gate)

Adopt the second position now, the first later. The namespace harmonisation (a one-line change per file) is executed immediately, independent of the integration timeline, so no future dependency is built against http://example.org/spc#.

Consequences

ontology/spc/spec/spc.ttl, ontology/spc/README.md, and the executable mirror tools/spc/python/src/spc/ontologies/spc.owl.ttl now use https://www.nebularis.org/neuro-semantic/lattice/spc# in place of http://example.org/spc# (executed in this slice).
ontology-architecture.md §3’s SPC description is updated to state this ADR’s position rather than “out of scope” (executed in this slice).
ADR-A01 (layer dependency order) is unaffected: SPC remains outside the Foundation→…→Behaviour dependency chain: it does not import from, or get imported by, any layer in that order.
Phase 3’s gate audit (per the epic’s own note) must confirm every workflow documented so far is in the uniform shape this ADR assumes, before Phase 4’s SPC lift is attempted.
This ADR does not author ontology/spc/projection/; that remains empty until Phase 4.