A Tight Upper Bound for Fully Dynamic Matching on the Line

Yash Kanoria

For m≥2 labeled supplies on [0,1], independent uniform demands and independent uniform replacement after each online match, the project proves a policy whose one-period root-mean-square cost, from every fixed initial inventory, has limsup at most (72000/log 2)·log(m+1)/m. After a scheduled m-period replacement phase, expected average cost including that phase obeys the same bound for every horizon N≥2m².

Sources for this record

What was already known

Kanoria’s earlier theorem gave a lower bound of order log(m)/m and an upper bound of order (log m)²/m in this model.

AI involvement AI-led

Kanoria directed and explained the project. The manuscript and repository credit ChatGPT/Codex agents with developing the retained hierarchical deletion policy and proof.

Agents developed the retained policy and proof under Kanoria's mathematical direction; exact model versions are not fully recorded.

Importance Notable

Matches the known lower-bound order for the specified fully dynamic one-dimensional matching model.

Limitations

The reported formal theorem covers the two upper-bound cost clauses. It does not certify an executable time or memory bound, and the earlier lower bound remains prior human work. No independent human line-by-line proof check is documented.

Technical verification Formal (Lean 4/Mathlib kernel, Comparator and NanoDa)

The source reports a Lean kernel-checked proof of the two upper-bound clauses and Comparator/NanoDa replay. Operational complexity and the lower-bound corollary are outside the checked statement.

Formal checking

Repository reports Lean verification, statement comparison, axiom audit and replay of the two upper-bound clauses.

Checker
Lean kernel, Comparator and NanoDa
Scope
FD1D.V5.Palomar.optimalDynamicMatchingUpperBound: RMS and finite-horizon expected-cost clauses
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Full

Kanoria's manuscript explains the central policy and analysis in Sections 1–4 and its detailed Bellman proof; this is human-facing explanation of the assessed upper bound, separate from proof checking.

Correction and publication history

2026-10-18 · publication

The compared Lean theorem covers two upper-bound cost clauses for the specified policy.

Read this published revision