This record contains the manuscript and reproducibility package for The Local Modulus-81 Theorem. The paper proves a local finite theorem at modulus 81 for a finite reverse-transport model associated with the 3x+1 map. The result is local and finite in scope: it does not prove global convergence, higher-scale persistence, a forward odd-only bridge, or the global 3x+1 conjecture. The accompanying archive includes: PDF manuscript, LaTeX source, BibTeX file, audit scripts, audit outputs, SHA256 manifest, compile report, and verification report. The computational checks use exact integer and rational arithmetic to recompute the finite objects used in the paper, including the matrix/vector data, residual identities, witness values, dyadic channel checks, and the pairing-law counterexample.
Itay Fadida (Mon,) studied this question.