First-contraction quarter gap from a supplied numerical certificate
ProvedCollatzWork.firstContraction_quarter_of_certificatecollatz-work-import
Let be the shortcut Collatz map: for even and for odd . Write for its -fold iterate, with . Let count the odd inputs among the first shortcut steps, and let ; recursively for an even input and for an odd input. For , define , , and . A first coefficient contraction at time means , , and for every . Its existence is a hypothesis.
Let , , with a first coefficient contraction at and . Assume . Then
This isolates the exact numerical certificate needed by the orbit argument.
Preamble
import Std import Init.Grind.Ordered.Module import Definitions.Def_CollatzWork_ConvergenceStatement import Definitions.Def_CollatzWork_QuarterGapStatement import Theorems.Thm_CollatzWork_orbitAffine import Theorems.Thm_CollatzWork_mechanicalEnvelope import Theorems.Thm_CollatzWork_affineQuarterCertificate
Formal statement
theorem CollatzWork.firstContraction_quarter_of_certificate {n k d : Nat}
(hn : 0 < n) (hfirst : FirstCoefficientContraction n k)
(hreturn : shortcutIter k n = n + d)
(hcert : 4 * mechanicalMax (orbitOddCount n k) ≤
orbitOddCount n k * 2 ^ coefficientCrossingExponent (orbitOddCount n k)) :
4 * d < orbitOddCount n k := by sorry
Source