C.3.1:0 - Use This When

Use this pattern when work must recover one reusable kind, decide whether one kind is a subkind of another, or decide whether the same kind continues across a changed KindSignature edition.

What goes wrong if missed. A source or practice label becomes an identity key, U.SubkindOf carries dependency or construction, a finite sample is mistaken for a universal order, mutually classifying kinds are silently merged, or a changed declaration is treated as automatically new or automatically harmless.

What this buys. The user gets an operational kind-continuity test, a replayable subkind test, and a small preorder that remains distinct from declaration identity, current extension, evidence, bridging, and public naming.

Primary EntityOfConcern. One U.Kind individual recovered through its candidate domain, operative membership condition, intended member/non-member distinction, and continuity rule; or one proposed U.SubkindOf relation between exact kind participants within declared applicability.

First useful move. Write the ordinary claim first: CoolingPumpKind is a subkind of PumpKind because every candidate that satisfies the declared cooling-pump condition also satisfies the pump condition. Then name the exact criteria and applicability that make that statement true. Introduce an occurrence designator or formal equivalence grouping only when a receiver uses it.

Not this pattern when. Use C.3.2 for a declaration, admissibility result, candidate classification, or extension; C.3.3 only for a claimed correspondence between independently identified distinct kinds; and E.24.UK when admitting another durable public kind rather than using an already admitted U.Kind individual.