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inductive definition def or abbrev high

MeasurementLevel

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Recognition Science models measurement via five levels where the absolute level corresponds to direct J-cost evaluation with J(1) = 0. Researchers formalizing Stevens' scales augmented by RS would cite this enumeration to fix configDim D = 5. The declaration is a direct inductive definition that derives decidability and finiteness instances.

claimThe measurement levels are the inductive type whose constructors are nominal, ordinal, interval, ratio, and absolute.

background

Recognition Science derives all measurement from the J-cost functional J(r) with J(1) = 0 as absolute zero deviation and J(r) > 0 for r ≠ 1. Stevens' classical hierarchy supplies nominal (1), ordinal (2), interval (3), and ratio (4) scales; RS adds absolute as the fifth level that measures J-cost directly. The module sets these five types equal to configDim D = 5. The upstream interval definition supplies the spacetime metric background used elsewhere in the unification layer.

proof idea

The declaration is a direct inductive definition that lists the five constructors and derives the DecidableEq, Repr, BEq, and Fintype instances.

why it matters in Recognition Science

This definition supplies the type for the measurementLevelCount theorem establishing Fintype.card = 5 and for the MeasurementTheoryCert structure. It realizes the framework step that five measurement types equal configDim D = 5, connecting Stevens' scales to the absolute J-cost scale. No open questions or scaffolding are touched.

scope and limits

formal statement (Lean)

  22inductive MeasurementLevel where
  23  | nominal | ordinal | interval | ratio | absolute
  24  deriving DecidableEq, Repr, BEq, Fintype
  25

used by (2)

From the project-wide theorem graph. These declarations reference this one in their body.

depends on (1)

Lean names referenced from this declaration's body.