Glossary

Strict definitions for the handful of words where English ambiguity actually leaks into specs. Keep this small (target ~20 terms). It is a precision tool, not a controlled grammar — past ~30 terms you are turning English into a formal language with keywords and killing the readable-SSOT thesis. When a spec uses one of these words in a load-bearing way, it means exactly what is below; if it needs a different sense, it must say so locally.

Emptiness / presence

absent — the field/value was never supplied; the key does not exist.
empty — the value exists and is the zero-length form ("", [], {}).
null — an explicit “no value” marker distinct from absent and empty. A spec must not use “null” to mean absent or empty without saying which.
undefined — outside the specified domain; behavior is not specified here. An undefined case is a finding unless named as explicit out-of-scope.
invalid — present and well-typed but failing a stated precondition; produces a named rejection, not undefined behavior.

Time

immediately — within the same atomic action, before it returns. Not “soon.”
eventually — guaranteed to occur in finite time, with no stated bound.
within X — at or before X has elapsed, measured by the named monotonic clock.
now — the injected clock value at action time (never read inside the transition — see execution-contract.md, Logic Confinement).
after / before / most-recent — by insertion order unless a spec explicitly says wall-clock order (clocks may be non-monotonic; insertion order is authoritative).

Identity / equality

same — identical opaque identity (same id), not equal content.
equivalent — equal under a stated normalization, not necessarily the same id.
matches — satisfies a stated predicate; the predicate must be named.
unique — no two distinct entities share the value, across the stated scope (name the scope: per-instance, per-store, system-wide, for-all-time).

Modality

must — a hard requirement; violation is a defect.
may — optional; both doing and not doing it are conformant.
should — recommended; a deviation must be justified. (Avoid in invariants — an invariant is must or it is not an invariant.)

Separation

tombstone (2026-06-11) — the corpus does not use the working noun from “Separation of Concerns” (the ancestor principle’s name, permitted only in that title-case form — lint rule J). The unit of separation is the concept (realized in the library as the atom; a composition is the wiring of concepts, never a new concept — Jackson’s wiring-not-primitive rule, made structural by the composition-state rule); a pre-triage item in the guided tool is a candidate concept (a stage, consumed by triage — promoted or rejected, never outliving Phase 1). Atom and composition are defined in readme.md; the thesis phrase is claimed in the-spec-layer.md.
application — a deployed build output; output-level vocabulary only, never a spec-layer artifact. The canonical layer has exactly two artifact kinds: atomic concepts and compositions thereof (lint rule K). Component / module / service are likewise projection-internal — generated, never authored.

Status: stub, 2026-06-04. Seeded from the recurring ambiguity classes (emptiness, time, identity, modality). Add a term only when a real spec ambiguity forced it — not speculatively.