Exhaustive coefficient reduction for binary rows - #1686
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August 6, 2026 15:30
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/ok to test 852fa50 |
CI Test Summary8 failed · 23 passed · 0 skipped |
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/ok to test c836178 |
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/ok to test d0323a6 |
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Aug 10, 2026
| // points, which are supersets of BHW's ceilings and roofs because we skip their ordering condition. | ||
| // That costs nothing: with all coefficients positive the activity is monotone, so the maximum of | ||
| // w.x over the feasible points is attained at a maximal one and the minimum over the infeasible | ||
| // points at a minimal one. Checked exhaustively over 9.4M (row, weight) pairs against full 2^k |
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I think we can remote the sentence starting with "Checked"
| // points at a minimal one. Checked exhaustively over 9.4M (row, weight) pairs against full 2^k | ||
| // equivalence, in both directions, before landing. | ||
| // | ||
| // BHW's minimization is not implemented. Section 5 obtains the minimum equivalent inequality by LP |
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I think we can remove this paragraph
| // vectors for a 12-entry row, measured at 187us for the worst shape. Lemma 3.6 supplies the lower | ||
| // bound that seeds and prunes the search. | ||
| // | ||
| // TODO: extend the fallback path to the row generation of Section 6. On the PaPILO-reduced corpus |
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Let's shorten this an avoid giving numbers on an instance specific example.
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Add a Bradley–Hammer–Wolsey coefficient-reduction presolver for short, one-sided constraints over binary variables. It integerizes and normalizes eligible rows,
searches for smaller equivalent integer weights, and retains only rewrites that preserve binary solutions without weakening the original row’s LP relaxation.
Add targeted and randomized tests covering rational coefficients, both inequality orientations, mixed signs, cache behavior, rejection cases, and exhaustive
preservation of the 0/1 feasible set.
This is useful to reduce fractional rows to pure integral for the bnatt* class to allow for a future CPUFJ fast path.
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