FPF Reference

E.10.D2:4.1 The triad (applies to any intensional U.T)

Preface node heading:e-10-d2-4-1-the-triad-applies-to-any-intensional-u-t:41236

Content

Terminology discipline (normative). Say I/D/S layers when you mean the stratified order with a Spec‑gate; say I/D/S triad only to note three‑ness without order or dependency. Do not call I/D/S a “plane”. Reserve plane for uses explicitly defined elsewhere (e.g., CHR:ReferencePlane and status families). Layer semantics (clarity). I‑layer = kernel/intensional type (non‑epistemic; not a episteme) . D‑layer and S‑layer = epistemic Knowledge Units (KUs). The Spec‑gate upgrades a Description to a Specification only under declared checkability and harness conditions (unchanged).

For every intensional type U.T:

  • Intension — U.T. The thing itself (e.g., U.Role, U.Method, U.PromiseContent, U.System, U.Work, U.RCS, U.RSG). It does not contain documents, checklists, or carriers; it is not a runtime event or a file.

  • Description episteme — U.TDescription(@Context) A Context‑local knowledge unit that characterises U.T with labels (Tech/Plain), glosses, and, when applicable, Role Characterisation Space (U.RCS), Role State Graph (U.RSG), and state conformance checklists. Readable, precise, didactic; may reference evaluation criteria but does not assert testable “shall”s by itself.

  • Specification episteme — U.TSpec(@Context) A Context‑local knowledge unit that states testable invariants for U.T and is bound to an acceptance harness. Normative, verifiable, suitable for SCR/RSCR (F.15).

Key phrasing discipline. Intensions are characterised by (not “contain”) RCS/RSG/checklists, which live in the Description/Spec. Terminology guard. To avoid collisions with ReferencePlane and other semantic planes, the I/D/S triad is referred to as I/D/S Layers (Intension Layer - Description Layer - Specification Layer). The word plane is reserved for semantic planes (Role/Status/Measurement/Type‑structure/Method/Work, etc.) and for the ReferencePlane field used in describedEntity/assurance.