Limits RegistryPUBLIC RECORD
Limits RegistryMIPLIB is the standard benchmark library for mixed-integer programming — optimization problems over both continuous and integer-valued variables, used across logistics, scheduling, and engineering. This record cites the proven optimal objective value for the MIPLIB instance gr4x6, according to version 36 of the official solution catalog.
The question, scope, and sources behind this Registry record.
MIPLIB is the standard benchmark library for mixed-integer programming — optimization problems over both continuous and integer-valued variables, used across logistics, scheduling, and engineering. This record cites the proven optimal objective value for the MIPLIB instance gr4x6, according to version 36 of the official solution catalog.
Minimize the objective of the MIPLIB 2017 benchmark model gr4x6.
Change a parameter to stress-test whether a proposed result is still inside the published specification. This is an audit aid, not a proof checker.
Current frontiers derived from accepted Claims.
Accepted lower and upper Claims meet at this value; the optimization gap is closed.
The frontier is not sacred
Most progress starts with a disagreement that survives contact with evidence. If you can push the known lower bound up or pull the upper bound down, show us the work.
≥ when you have shown that at least this value is achievable.≤ when you have shown that anything above this value is impossible.No vibes. State the value, define the scope, and link the paper, proof, code, or reproduction that lets another person check it. Editors review every challenge before the public record changes.
Challenge this recordAssertions tied to evidence, attribution, and review.
The frontier as it changed over time.
Only accepted Claims matching the current specification contribute to the displayed bounds. Strict inequalities remain open; contradictory Claims require editorial review.
No community challenges are recorded for this published version yet.
View timeline ↗2 accepted Claims, with 2 linked evidence records.
Permanent ID limitsregistry.com/limits/LR-002283
No active verified bounties are linked to this Limit.
View verified bounty tracker ↗No accepted machine-checked reproductions are recorded for this Limit.
Limits Registry. LR-002283. MIPLIB optimal objective — gr4x6. 2026.