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Kepler conjecture: source finite-container theorem

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KeplerMission.kepler_finite_container

by Minghui · Sep 27, 2026 · Mathlib c5ea003 (Lean v4.30.0)

discrete-geometrykeplersphere-packing

For every unit-sphere packing V in Euclidean three-space, there exists a real c such that, for every real r≥1, the number of centers in the open ball B(0,r) is at most πr³/√18+cr². Distinct centers are separated by at least 2. The constant may depend on V but not on r. No finiteness, periodicity, saturation, origin membership, density limit or uniqueness assumption appears. This is the displayed formal source theorem.

∀V, Pack⁡(V)⟹∃c∈R, ∀r≥1,NV(r)≤πr318+cr2.\forall V,\ \operatorname{Pack}(V)\Longrightarrow\exists c\in\mathbb R,\ \forall r\ge1,\quad N_V(r)\le\frac{\pi r^3}{\sqrt{18}}+cr^2.∀V, Pack(V)⟹∃c∈R, ∀r≥1,NV​(r)≤18​πr3​+cr2.

Source. Hales et al., A Formal Proof of the Kepler Conjecture (2017), https://doi.org/10.1017/fmp.2017.1, §3 p.6, exact HOL Light display; general/the_main_statement.hl:the_kepler_conjecture.

Formalization note. Direct source theorem.

Preamble
import Definitions.Def_Kepler_MissionContracts
set_option autoImplicit false
Formal statement
namespace KeplerMission
theorem kepler_finite_container : ∀ V : Set Space, IsPacking V → ∃ c : ℝ, ∀ r : ℝ, 1 ≤ r →
    (centerCount V 0 r : ℝ) ≤ Real.pi * r ^ 3 / Real.sqrt 18 + c * r ^ 2 := by sorry
end KeplerMission
Source
Hales et al., A Formal Proof of the Kepler Conjecture (2017), https://doi.org/10.1017/fmp.2017.1; §3 p.6, exact HOL Light display; general/the_main_statement.hl:the_kepler_conjecture; https://github.com/flyspeck/flyspeck/blob/1ce0353008eba83d3c76ae9a25c3c242e4802d53/text_formalization/general/the_main_statement.hl; https://publicationsthomashales.wordpress.com/wp-content/uploads/2016/03/densespherepackings.pdf
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What the Lean code literally says, in plain math · gpt-6

This defines, without proving, the proposition that for every packing V⊆R3V\subseteq\mathbb R^3V⊆R3 there exists a real ccc such that NV(0,r)≤πr3/18+cr2N_V(0,r)\leq\pi r^3/\sqrt{18}+cr^2NV​(0,r)≤πr3/18​+cr2 for all real r≥1r\geq1r≥1. Packing requires distance at least 222 only between distinct centers. The count is over the open origin-centered ball and is zero by convention if that intersection is infinite. The number ccc is independent of rrr, may depend on VVV, and need not be nonnegative. Empty sets are included; neither saturation nor any milestone is a hypothesis of this proposition.

Human review
  • Endorsed by Shuze Chen · Sep 27, 2026

    Confirmed by the moderator at approval.

  • Endorsed by Minghui · Sep 27, 2026

    Confirmed by the mission captain (proposal self-audit).

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