A.6.1:10 - Rationale

U.Mechanism earns a dependent durable name because many later patterns rely on one reusable declaration of operations, laws, admission predicates, and applicability. Treating that declaration as only a table format loses identity. Treating it as the realizing system or method makes every implementation change look like a law change.

The declaration uses the U.Signature identity and content settlement because its reusable vocabulary, laws, applicability, and dependencies have the same episteme discipline. It remains a separate dependent U-kind because operation algebra and admission semantics create recurring action-facing claims that an ordinary signature does not govern. This dependence does not assert a C.3 subkind relation by itself.

The actual application and each binding are separate because the stable declaration can be reused with different actual values, and the same value can participate under different declaration-local meanings. Exact application and binding predicates, extents, and identities distinguish actual participation from a plan, description, reference, compatible type, or result record and keep work-input and work-result relations domain-specific.

The realization relation is separate because several entities can realize the same declaration and one entity can realize it only for a bounded scope and interval. Evidence can change without changing that world-side or semantic relation. This keeps mechanism evolution local and makes failure diagnosis practical.

Progressive explicitness serves didactic primacy. The pattern begins with a readable engineering question and a mantra, then introduces typed content only when reuse requires it. The mantra improves recall; A.22.CGUS enters only for an independently identified structure of potential continuations, while an enabled continuation, Work occurrence, and actual Transformation remain separate values.