Formal models and scripts: distance-feature-pruning

Tools: SMT-LIB (Z3/cvc5), Python

These are the working models and scripts this part of the hunt used. Some encode the code as it is (a counterexample is the expected result), others a fixed or correct variant; read the header comment of each file. Paths inside them were replaced by placeholders such as $LUCENE (a Lucene checkout) and $WORK.

Findings

• LatLonPoint.newDistanceFeatureQuery can skip a competitive document under top-k pruning: computeMaxDistance returns the lower end of its 1 m binary search, and the pruning box built from that radius adds only a 7 cm pad (finding LFV-379; repro · finding page)

Files

• latlon-distance-feature-bisection-gap/model/decode_model.py (used for LFV-379)
• latlon-distance-feature-bisection-gap/model/gen_smt.py (used for LFV-379)
• latlon-distance-feature-bisection-gap/model/p1_q2_no_goal.smt2 (used for LFV-379)
• latlon-distance-feature-bisection-gap/model/p2_q2_26_steps_insufficient.smt2 (used for LFV-379)
• latlon-distance-feature-bisection-gap/model/p3_q2_24_steps_insufficient.smt2 (used for LFV-379)
• latlon-distance-feature-bisection-gap/model/q1_postcondition.smt2 (used for LFV-379)
• latlon-distance-feature-bisection-gap/model/q2_reach_2048.smt2 (used for LFV-379)
• latlon-distance-feature-bisection-gap/model/q2_reach_full.smt2 (used for LFV-379)

How to run

• SMT-LIB: z3 <file>.smt2 or cvc5 <file>.smt2 (sat with a model is a counterexample where the query asks for one).
• Python: python3 <file>.py; scripts that import z3 need the z3-solver package.

Snapshot of 2026-11-03. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.