pith. sign in
module module moderate

IndisputableMonolith.Cost.FunctionalEquation

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Cost.FunctionalEquation supplies the log reparametrization converting the multiplicative cost functional equation into additive d'Alembert form. Modules handling Aczél classification and T5 uniqueness cite it to reduce the Recognition Composition Law to classical smoothness results. The module consists of the core definition G_F(t) := F(exp t) together with supporting evenness and derivative lemmas.

claim$G_F(t) := F(e^t)$ for a function $F$ obeying the Recognition Composition Law, together with the induced even function $H$ satisfying $H(t+u)+H(t-u)=2H(t)H(u)$ and $H(0)=1$.

background

The module works inside the Cost domain after the Recognition Composition Law has been stated. It imports the AczelClass typeclass interface that packages the d'Alembert smoothness bootstrap. The central object is the change-of-variable $G_F(t)=F(e^t)$ that turns the multiplicative arguments of the original equation into additive arguments, allowing direct appeal to the classical d'Alembert equation.

proof idea

This is a definition module, no proofs.

why it matters in Recognition Science

The reparametrization is used by AczelClassification, AczelProof and ContDiffReduction to obtain the ODE $H''=H$ and thereby close the T5 uniqueness step. Downstream modules such as CostAlgebra and CostUniqueness import it to separate the Aczél-dependent closure from the axiom-free core.

scope and limits

used by (21)

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depends on (2)

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declarations in this module (62)