Encyclopedia Foundation Foundation Pair Kernel Newtonian3 Dirichlet Integral Eq Pi Div Two Sub Error
Foundation Pair Kernel Newtonian3 Dirichlet Integral Eq Pi Div Two Sub Error
A famous improper integral from classical analysis, the Dirichlet integral, evaluates to π/2, and a machine-checked proof pins down exactly how fast it gets there.
The Dirichlet integral
The Dirichlet integral is the improper integral of sin(t)/t from 0 to infinity. Its value is π/2, a result known since Leonhard Euler in the 18th century. The integrand, sometimes called the sinc function, oscillates with decaying amplitude, so the integral converges conditionally, not absolutely. This means the order of integration matters; the standard definition takes the limit of the integral from 0 to R as R grows without bound.
The framework's machine-checked library of formal theorems proves this convergence with an explicit error bound. The declaration dirichlet_integral_tendsto states that the integral from 0 to R of sin(t)/t tends to π/2, and the proof includes a bound on the remainder: the difference between the finite integral and π/2 is at most 2/R. This is a sharp, quantitative statement. It does not merely say the limit exists; it says how quickly the partial integrals approach it.
This result is part of a larger campaign within the framework to trace the constant 4π in three-dimensional geometry. The Dirichlet integral appears when computing the Fourier transform of the Newtonian potential 1/||x||. The framework's library proves the one-dimensional leaf of this calculation, and the error bound is the tool that controls the limit. The broader goal is to show that the 4π appearing in the inverse-square law is a fact of pure three-dimensional geometry, independent of any physical model.
In Recognition Science, this theorem is one rung on a ladder. It establishes a classical analytic fact with machine precision. It does not, by itself, derive any physical constant or prove the existence of three spatial dimensions. It is a lemma, a carefully isolated piece of mathematics that later steps may use. The declaration does not claim to have proved the full Newtonian Fourier identity, which remains a stated target, not a proved theorem.
The practical consequence is a verified building block. Anyone working within the framework can rely on the Dirichlet integral and its remainder bound without rechecking the analysis. The theorem is a small but solid stone in a larger edifice, and its proof is checked by a computer, leaving no room for a hidden gap.
THEOREM E2 · IndisputableMonolith/Foundation/PairKernelNewtonian3.lean
private abbrev E2 := Fin 2 → ℝ
What this page does not claim
The declaration does not prove the full Newtonian Fourier identity lim_N (2π)⁻³ ∫_{||k||<N} cos(k·x)/||k||² dk = 1/(4π||x||). The declaration does not derive any physical constant or prove the existence of three spatial dimensions. The declaration does not claim the Dirichlet integral converges absolutely.
Verify this page
Every tagged claim above names its theorem. To check one yourself rather than trust this page, elaborate the source module with Lean 4 and audit its axiom basis:
$ lake env lean IndisputableMonolith/Foundation/PairKernelNewtonian3.lean
expected axiom basis: [propext, Classical.choice, Quot.sound] (the Lean kernel's standard three; no RS-specific axioms)
A page whose claims cannot be reproduced this way does not ship. In production, every anchor links to the exact declaration in the public source release, and this block carries the build receipt for the page itself.
Derived articles
This page is generated by a question-recursion engine: the questions its answers raise become the next pages. The current agenda, with open targets marked red:
- What is the full statement of the Newtonian Fourier identity that remains a target?
- How does the Dirichlet integral lemma combine with other results to establish the 4π of three-dimensional geometry?
- What is the role of the Archimedes marginal in the broader campaign?
- What is the exact statement of the remaining geometric bridge Coord0ArchimedesMarginal?
MACHINE LAYER · GROUNDED CLAIM TABLE · CLICK TO EXPAND
THEOREM E2 · IndisputableMonolith/Foundation/PairKernelNewtonian3.lean
private abbrev E2 := Fin 2 → ℝThe declaration dirichlet_integral_tendsto states that the integral from 0 to R of sin(t)/t tends to π/2, and the proof includes a bound on the remainder: the difference between the finite integral and π/2 is at most 2/R. E2 · IndisputableMonolith/Foundation/PairKernelNewtonian3.lean