fpf.tools
Library / First Principles Framework (FPF) - Core Conceptual Specification
Jump to passage
In this reading
Source · lines 31759–31792

Link to current text

Published source confirmed at last check

Source changed 2026-10-03 11:52:20 UTC · snapshot created 2026-10-03 11:53:41 UTC · last check 2026-10-03 12:45:07 UTC

A.17:4 - Solution

Establish “Characteristic” as the one canonical construct for “what is measured.” In every FPF context, the aspect or trait being measured MUST be referred to as a Characteristic. This term replaces “axis” or “dimension” when they are used as names for the measured aspect; Plain aliases must keep that mapping clear. By fixing a single name and schema, we cleanly separate a Characteristic from its Scale (and Unit), and from any observed Value/Level on that scale. The solution also differentiates single-entity vs multi-entity cases and binds all measurements to the standard CSLC sequence.

To enforce this solution, the following rules apply:

  • A17-R1 (Canonical term). In all normative models and specifications, the measured aspect SHALL be referred to as a Characteristic. “Axis” and “Dimension” are not technical substitutes for the measured aspect.

  • A17-R2 (Entity vs. relation subtype). Each Characteristic MUST declare its intended arity. An Entity-Characteristic applies to exactly one bearer (e.g. Temperature of a reactor, Evolvability of a software module), whereas a Relation-Characteristic applies to an ordered tuple of two or more bearers (e.g. Distance between two sensors, Coupling between modules, Agreement among reviewers). The arity is part of the definition and must be explicit wherever it’s not obvious from naming.

  • A17-R3 (Characteristic space). When several Characteristics form a declared space, identify their slots, Scales and admissible values under A.19. State the constraints and additional structure required by its use. Use A.3.3.CC when compatible combinations must be constructed: it selects variables and constraints and compares implicit descriptions, parametrizations and finite sets. A.3.3 completes the state and transition account when the question concerns modeled change.

  • A17-R4 (Lexical guardrails). When naming the measured aspect, its scale, its value or position, or an evaluative result, normative text SHALL use the corresponding governed term: Characteristic, Scale, Unit, Level/Value, Coordinate, Score, Normalization or ScoringMethod. Do not use axis, dimension, metric, grade or property as an undeclared substitute for those constructs. A disciplinary term naming another defined subject keeps that meaning; a mathematical dimension or metric, for example, is not renamed Characteristic. A Plain alias may be used when its mapping is clear. Apply E.10 to an unresolved lexical question.

  • A17-R5 (Symbol policy). Γ is reserved for holonic composition; 𝒢 denotes a ScoringMethod from Coordinates to a Score. Documents SHALL NOT reuse Γ for a ScoringMethod.

  • A17-R6 (Scale order and preference). For an ordered Scale, use its order to compare values of the Characteristic: a higher temperature value means hotter. A use that ranks values by desirability SHALL declare its preference rule, such as higher-is-better, lower-is-better, a target or range, or another ordering. Describing or comparing magnitudes requires no preference rule.

  • A17-R7 (Scoring against preference). A ScoringMethod SHALL state how its score order represents the declared preference. Where one input is higher-is-better or lower-is-better, improving that input while holding the others fixed MUST NOT worsen the score, for admissible inputs under the stated conditions. Target-based preference is checked against its declared target or loss rule; the preferred direction may change across the target. A quantity calculation or unit conversion uses its measurement relation and Scale rules under A.18/C.16.

  • A17-R8 (Arity declaration). Authors SHALL mark a Characteristic as U.EntityCharacteristic (applies to exactly one bearer) or U.RelationCharacteristic (applies to an ordered tuple of two or more bearers). Examples: Cohesion → entity‑level; Coupling → relation‑level.

  • A17-R9 (Relational scale anchors). For relation‑level cases, the Scale’s admissible values SHALL be defined over the tuple domain (e.g., distances, similarities, inter‑role latencies). Ambiguity that re‑reads a relational Characteristic as unary is forbidden.

  • A17-R10 (Intension vs Description). The Characteristic remains the Characteristic EntityOfConcern; any rubric, catalogue of levels, or examples are Description epistemes. Keep the intensional Characteristic distinct from its descriptive episteme (cf. U.Episteme roles: Object–Concept–Symbol).

A.17:4.1 - CharacteristicSpace & Change Reasoning (Normative/Clarifying)

R17 - State-space use. When a change model uses a CharacteristicSpace, declare its Characteristics, Scales, units and admitted combinations under A.19. Add topology, distance or another structure when the inference relies on it.

R18 - Allowed changes and state recognition. For a model of change, state the allowed continuations and their conditions through A.3.3. Use a state predicate or checklist when the receiving use needs to recognize a condition. A.2.5 governs the particular case of a condition on an assignment to a system role; a gate or assurance use supplies its own required support.

I7 — Vector interpretation. A U.Coordinate vector may collect multiple coordinates for multi‑Characteristic reasoning; composition into a single Score, if desired, is an explicit new 𝒢 on that vector.