Pricing the Risk of Runtime Compression: Anytime-Valid Admission and a Served-Output Law for Compressed Serving State
Fanzhe Wei, Li Liu
cs.AI
Aug 16, 2026 · v1
TL;DR
Probabilistic kernels for anytime-valid admission and served-TV bounds are machine-checked in Lean 4 with 228 exported theorems and no sorry.
Abstract
Runtime compression of serving state trades quality for capacity with no priced guarantee: systems adapt precision on load signals with no soundness statement, and certified approaches budget request-level risk by a union bound over a pre-declared event count. We show the union budget exhausts on every long request in a production serving stack (100% of requests), and replace it with an anytime-valid, physically accounted ledger whose bound holds at every one of 352,333 admission calls on live traffic and which, in a pre-registered held-out confirmatory round, halves the exact-fallback rate at matched risk (0.30 -> 0.14) – coverage is bought at a price the account states. We then price the remaining distance from the certified witness to what a user experiences: a machine-checked design law (TV <= tanh(a_q w_thr)) turns the served-TV target into a threshold knob, and a three-layer audit of its instantiation – an operator-norm query envelope measured 1.5x from tight, a measured-ellipsoid replacement for the Cauchy-Schwarz ball that buys nothing (0.89x, held-out sound), and the gate's operating point ( 700x) – localizes the entire 1064x gap to the operating point, a price the law now states rather than an unknown. A priced bound is worth nothing on a request one has not seen, so the third link is the quantifier: exchangeable extrapolation across 80 serving histories replaces binary conformal prediction's vacuous certificates with order-statistic bounds that discriminate (0.41 against 0.51 calibration risk). All probabilistic kernels are Lean 4-checked (228 exported theorems, no sorry); which object deserves this machinery at all is settled empirically in a companion paper that adjudicates – and rejects – the natural alternative of certifying routing. What ships is an account: risk you can spend, a gap you can read off a law, and a bound that survives the request you have not seen.
Problem
Runtime compression of large-model serving state trades quality for capacity without a sound per-request accounting of the risk each precision decision incurs. Certified approaches budget request-level risk by a union bound that exhausts on every long request.
Approach
An anytime-valid ledger bounds cumulative realized loss instead of using a per-event union budget, with admission rules proven conservative. A machine-checked served-TV design law (TV <= tanh(a_q w_thr)) ties the controller threshold to a served-output quantity, replacing an earlier vacuous exponential-tilt softmax bound. Exchangeable extrapolation across serving histories provides order-statistic transfer bounds. All probabilistic kernels are verified in Lean 4 (228 exported theorems, no sorry).
Results
The anytime-valid bound held at all 352,333 admission calls on live traffic with zero violations, and halved the exact-fallback rate at matched risk (0.30 -> 0.14) in a held-out round. A five-arm serving-stack replication showed equal quality (1.000) across arms with the cumulative-loss gate holding a bounded account (99.97% peak) versus the union gate exhausting its budget.
| metric | union | cumloss 5e3 | cumloss 2e4 | cumloss 5e4 |
|---|
| budget exhaustion | 100% | — | — | — |
| fallback-to-exact (median) | 0.315 | 0.842 | 0.339 | 0.0079 |
| violations | 0 | 0 | 0 | 0 |
Dual-accounted admission by budget (union vs. cumulative loss)
| Arm | acc | risk ledger | fallback |
|---|
| FP8 safe | 1.000 | none | — |
| aggressive, no gate | 1.000 | none | — |
| gated, union budget | 1.000 | exhausts (99.4%) | 59.3% |
| gated, cumulative | 1.000 | bounded (99.97%) | 56.3% |
Five-arm equal-quality serving stack table