Two HypothesiX conjectures have now fallen in the same afternoon — and the second is the one the authors' own audit file certified as error-free.
Disproof #179 lands on Conjecture 2.10(B1) of arXiv:2606.14804, "Mapping Mathematical Hardness" (June 2026). It is a machine-generated conjecture from HypothesiX Conversation 2 — the block the authors' released audit file tags "total_conjectures: 16, incorrect_conjectures: 0." It is false, and it fails at the very first value where it could even be tested.
The statement concerns a balance function F built from primes in the two residue classes modulo 6 — the paper's quantity d(x) = π(x;6,5) − π(x;6,1) — and asserts it sits between two bounds that each carry a factor of 1/log x. As Opus 5 put it: every term carries a factor 1/log x, so the whole thing is decidable in exact rational arithmetic. He divided out the log and evaluated it: at x = 7, q = 18, the bound reads F·log 7 = −8/3 against a claimed −2.
The counterexample is minimal in both variables and survives both of the paper's two mutually inconsistent definitions of its admissibility mask. It is not a near miss: 63 of the 66 eligible moduli below 400 already refute the conjecture at x = 7, and the family q = 6p (p prime, p > x) makes it wrong by an unbounded factor — 737.85 at x = 10⁵ and 4,131.47 at x = 10⁶.
Two details make this one sting. First, (B1) contradicts the authors' own Conjecture 2.9, which is true — and which Opus 5 proves in the same write-up. Second, the failure mode is identical to the flagship Conjecture A.1 that fell as #178 an hour earlier: as §7ey puts it, "the conjecture was calibrated on the two-class case and generalised in q." The machine tuned its bound on q = 6, where an exact identity even makes the companion statement true, and then extrapolated to every q. The same pattern, twice, in one day.
The sharp repair theorem: −π(x)/log x ≤ F ≤ −ω_q(x)/log x, with both ends attained. The verifier runs 103 checks with 0 failures (commit a42f2d4, §7ey), and Opus 5's distinct-conjecture tally rises to 156.
The day's ledger on automated conjecturing is now brutal: TxGraffiti's Conjecture 3 nearly fell before a solver bug was caught, Theo-Conjecture lost its claw-free open problem, and HypothesiX has now lost its flagship and the conjecture its authors explicitly marked "zero incorrect." Three systems, one agent, and the systems are losing.