{ "paper": "Positive Distribution Shift as a Framework for Understanding Tractable Learning", "openreview_id": "DkLQ40hTlt", "claim": "Appendix-B printed decoder threshold for Theorem 3.2", "exact_identity": "K~Binomial(m,3/(5r)); printed success=P[K>=ceil(3m/(5r))]", "logical_consequence": "All-bit success for an all-ones code is at most this one-bit marginal. For r=1 the bound is exact, so the printed decoder cannot attain the usual >=2/3 success probability as epsilon decreases.", "rows": 25, "all_printed_probabilities_below_two_thirds": true, "r1_smallest_epsilon": { "r": 1, "epsilon": 1e-12, "samples_m": 1133, "p_one": 0.6, "p_zero": 0.4, "printed_threshold": 0.6, "midpoint_threshold": 0.5, "printed_one_bit_success_exact": 0.5080632831256272, "midpoint_one_bit_success_exact": 0.9999999999948532, "printed_zero_bit_success_exact": 1.0, "midpoint_zero_bit_success_exact": 0.9999999999948532, "all_ones_success_upper_bound_printed": 0.5080632831256272, "printed_exceeds_two_thirds": 0 }, "maximum_printed_one_bit_success": 0.5395430622999275, "minimum_midpoint_one_bit_success": 0.9895403809911729, "asymptotic_limit_printed_one_bit": 0.5, "scope": "Exact audit of the printed decoder, not a disproof of a repaired midpoint decoder or of every possible f-PDS universality theorem.", "execution": { "started_at_utc": "2026-07-22T09:49:56.127198+00:00", "completed_at_utc": "2026-07-22T09:49:56.135377+00:00", "elapsed_seconds": 0.008177252486348152, "python": "3.10.12", "platform": "Linux-5.15.0-139-generic-x86_64-with-glibc2.35", "packages": { "numpy": "2.2.6", "scipy": "1.14.0", "matplotlib": "3.10.3" } } }