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No nontrivial Syracuse cycle state below 2786502

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syracuse_no_cycle_below_2786502

by FakeMink · Oct 2, 2026 · Mathlib 0df444a (Lean v4.33.1)

collatzcyclesfinite-verificationnumber-theory

Let T(n) be the odd part of 3n+1, the accelerated Syracuse map. If m and p are natural numbers with m>0, p>0, m<2786502 and T^p(m)=m, then m=1. The return time need not be least and the starting state need not be the cycle minimum. This is a bounded cycle-state exclusion, not a claim that all Collatz trajectories converge or that every possible cycle has been excluded.

Preamble
import Mathlib
import Definitions.Def_syracuseStep

set_option autoImplicit false
Formal statement
theorem syracuse_no_cycle_below_2786502 (m p : ℕ) (hm : 0 < m) (hp : 0 < p)
    (hlt : m < 2786502) (hcyc : syracuseStep^[p] m = m) :
    m = 1 := by sorry
Source
Finite extension of the public Proved syracuse_no_cycle_below_2310000, https://prove2.me/theorems/73735589-bbad-479f-8d7e-375fd2f82875 . Credits existing workspace CollatzFiniteDescent and CollatzFiniteDescentChunks checker/soundness modules, CollatzFiniteDescentExtensionChunk000 through047, CollatzFiniteDescentExtendedBand, CollatzCycleTools and CollatzCycleThreshold. Reuses the48 historical extension chunks covering odd states2307463 through2786501; exact new-band reindex is213284 and new count238251. A flattened source-only completed-proof candidate accompanies this draft. Historical checking is provenance, not new kernel acceptance or publication.

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