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IndisputableMonolith.Gravity.SevenGaps.ClassPushforward

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Defines the class-pushforward bookkeeping for the Seven Gaps path-sum: labeled fibers of quotient classes, fiber cardinality, and class mass as fiber size times the measure weight. Equates the configuration sum Z to a sum over triangulation classes of class masses. Gravity and quotient-first Z constructions import it to separate labeled configurations from orbit classes under Aut.

claimFor a quotient map $\pi:\alpha\to Q$, the labeled fiber of a class $q\in Q$ is $\{a\in\alpha:\pi(a)=q\}$. Fiber cardinality and class mass satisfy $\mathrm{classMass}(q)=|\mathrm{fiber}(q)|\cdot\mu(q)$. The path-sum $Z$ equals the pushforward sum $\sum_q\mathrm{classMass}(q)$, and likewise for the RS path-sum $Z_{\mathrm{RS}}$.

background

Seven Gaps Lane 2 builds a proved path-sum measure $Z_{\mathrm{RS}}$ on a scoped finite configuration class BoundedComplex B (Fintype via an explicit coding equivalence). Configurations carry bounded incidence data; the measure is a weighted sum over those labeled objects.

When one passes to triangulation classes (orbits under automorphism), the same total must be rewritten as a sum over classes. This module supplies the elementary fiberwise dictionary: the preimage of a class under the quotient map, its cardinality, and the class mass (cardinality times the weight of a representative). Decidability of membership is classical noncomputable bookkeeping, not an algorithmic claim.

The setting is pure finite-sum reindexing. No continuum limit or physical mass formula is invoked here; the objects are combinatorial weights on a finite type.

proof idea

Definition-and-lemma module, not a single deep theorem. Fibers and membership are set-comprehension defs. Fiber cardinality is the Fintype card of the fiber. Class mass is defined as that card times the measure weight $\mu$.

The main identities are finite-sum rewrites: a sum over labeled configurations equals the sum over quotient classes of the fiberwise inner sums; when the weight is constant on fibers this collapses to $\sum_q |\mathrm{fiber}(q)|\cdot\mu(q)$. Equivalence of quotient constructors is the standard Quotient.eq direction. Equalities $Z=\mathrm{classPushforward}$ and $Z_{\mathrm{RS}}=\mathrm{classPushforward}$ are then one-line applications of those rewrites.

why it matters in Recognition Science

Feeds the quotient-first path-sum object in QuotientFirstZ, which constructs $Z_q B, w_q=\sum_{q:\mathrm{TriangulationClass},B}(1/|\mathrm{Aut}(\mathrm{out},q)|)\cdot w_q(q)$ under the P2c panel lock. Also imported by FreudenthalTorusClassMass, the Crux-2 consistency gate that compares labeled versus class mass for the canonical torus (after the panel's wording repair that the original "$N^{-3}$ suppression" claim was ill-posed).

Without fiberwise pushforward, one cannot move between the proved labeled path-sum measure of PathSumMeasure and any class-orbit formulation required by the Seven Gaps gravity lane. The module is pure bookkeeping infrastructure for that passage.

scope and limits

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.

declarations in this module (24)