FAILURE MAP
← Case archive

FA-99066 / Learning rate schedules / Open access

Milestone decay counts milestones after the requested step · case 01

Milestone decay counts milestones after the requested step.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Milestone comparisons exclude the exact update index.

THE FAILURE

Milestone comparisons exclude the exact update index.

Unsuccessful approach: Shifting the comparison forward applies a milestone before its configured step.

Case contract

Multiply base by gamma once for each milestone <= step.

Why this case matters

A deterministic scalar schedule makes step-to-rate mapping explicit for a small training loop.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(step, base, gamma, milestones):
    return base*gamma**sum(m<step for m in milestones)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
ms=[2,4,7]; check('at milestone',solve(2,16,0.5,ms),8); check('before',solve(1,16,0.5,ms),16); check('between',solve(3,16,0.5,ms),8); check('second',solve(4,16,0.5,ms),4); check('empty',solve(9,7,0.2,[]),7); check('past all',solve(8,16,0.5,ms),2)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
at milestone16.08Failed
before16.016Passed
between8.08Passed
second8.04Failed
empty7.07Passed
past all2.02Passed

SHA-256 / 04ec1a7e3ffff3f78a304895b9a93b7973fcaa5f257e6a856630ca70f7bf2cb2

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(step, base, gamma, milestones):
    return base*gamma**sum(m<=step+1 for m in milestones)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
ms=[2,4,7]; check('at milestone',solve(2,16,0.5,ms),8); check('before',solve(1,16,0.5,ms),16); check('between',solve(3,16,0.5,ms),8); check('second',solve(4,16,0.5,ms),4); check('empty',solve(9,7,0.2,[]),7); check('past all',solve(8,16,0.5,ms),2)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
at milestone8.08Passed
before8.016Failed
between4.08Failed
second4.04Passed
empty7.07Passed
past all2.02Passed

SHA-256 / 782c64af694c2725d7be151bc645c1ad5b4d61d7847ff7632abfd0bb9435df87

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 6 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Sign in to the archive ↗

Verification & scope

These are toy scalar contracts with integer steps and finite parameters; they do not model framework defaults or optimizer state. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-30T16:48:19.909905+00:00.

Case digest / 39c250784776556f52b24f489ad1788f9afcb99efaa9a80423c4a8d9d40563b2