FAILURE MAP
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FA-100621 / Mixture of experts dispatch / Open access

Combine weights are normalized across unrelated tokens · case 01

Combine weights are normalized across unrelated tokens.

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

ROOT CAUSE

All routes share one denominator.

THE FAILURE

All routes share one denominator.

Unsuccessful approach: Using the first route’s token as the denominator group omits other tokens.

Case contract

Rows [token,expert,weight]; return rows in order with each weight divided by its token total.

Why this case matters

A deterministic toy router makes this dispatch decision independently inspectable.

1 / The failure

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

N = 1
observations = []
def solve(routes):
    total=sum(r[2] for r in routes)
    return [[t,e,w/total] for t,e,w in routes] if total else []
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
rows=[[0,'a',N],[0,'b',1],[1,'c',2*N],[1,'d',N]]
check('separate sums',solve(rows),[[0,'a',N/(N+1)],[0,'b',1/(N+1)],[1,'c',2/3],[1,'d',1/3]])
check('one token',solve([[0,'a',2],[0,'b',2]]),[[0,'a',0.5],[0,'b',0.5]])
check('singleton',solve([[N,'x',N]]),[[N,'x',1.0]])
check('empty',solve([]),[])
check('zero token omitted',solve([[0,'a',0],[1,'b',N]]),[[1,'b',1.0]])
check('three tokens',solve([[0,'a',1],[1,'b',1],[2,'c',1]]),[[0,'a',1.0],[1,'b',1.0],[2,'c',1.0]])
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
separate sums[[0, 'a', 0.2], [0, 'b', 0.2], [1, 'c', 0.4], [1, 'd', 0.2]][[0, 'a', 0.5], [0, 'b', 0.5], [1, 'c', 0.6666666666666666], [1, 'd', 0.3333333333333333]]Failed
one token[[0, 'a', 0.5], [0, 'b', 0.5]][[0, 'a', 0.5], [0, 'b', 0.5]]Passed
singleton[[1, 'x', 1.0]][[1, 'x', 1.0]]Passed
empty[][]Passed
zero token omitted[[0, 'a', 0.0], [1, 'b', 1.0]][[1, 'b', 1.0]]Failed
three tokens[[0, 'a', 0.3333333333333333], [1, 'b', 0.3333333333333333], [2, 'c', 0.3333333333333333]][[0, 'a', 1.0], [1, 'b', 1.0], [2, 'c', 1.0]]Failed

SHA-256 / 85b69c9b499a4fa72a847a3913240a1d9cea709b10d8b0c54c6a344f487ffd16

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(routes):
    first=routes[0][0] if routes else None; total=sum(w for t,e,w in routes if t==first)
    return [[t,e,w/total] for t,e,w in routes if t==first] if total else []
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
rows=[[0,'a',N],[0,'b',1],[1,'c',2*N],[1,'d',N]]
check('separate sums',solve(rows),[[0,'a',N/(N+1)],[0,'b',1/(N+1)],[1,'c',2/3],[1,'d',1/3]])
check('one token',solve([[0,'a',2],[0,'b',2]]),[[0,'a',0.5],[0,'b',0.5]])
check('singleton',solve([[N,'x',N]]),[[N,'x',1.0]])
check('empty',solve([]),[])
check('zero token omitted',solve([[0,'a',0],[1,'b',N]]),[[1,'b',1.0]])
check('three tokens',solve([[0,'a',1],[1,'b',1],[2,'c',1]]),[[0,'a',1.0],[1,'b',1.0],[2,'c',1.0]])
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
separate sums[[0, 'a', 0.5], [0, 'b', 0.5]][[0, 'a', 0.5], [0, 'b', 0.5], [1, 'c', 0.6666666666666666], [1, 'd', 0.3333333333333333]]Failed
one token[[0, 'a', 0.5], [0, 'b', 0.5]][[0, 'a', 0.5], [0, 'b', 0.5]]Passed
singleton[[1, 'x', 1.0]][[1, 'x', 1.0]]Passed
empty[][]Passed
zero token omitted[][[1, 'b', 1.0]]Failed
three tokens[[0, 'a', 1.0]][[0, 'a', 1.0], [1, 'b', 1.0], [2, 'c', 1.0]]Failed

SHA-256 / 98ef609ee66eb4e9fd1f4ecc0dfbb2b4c2999b4499ea45af8f81d27f3a133818

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.

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Verification & scope

Inputs are finite toy scores and routes; the contract does not model a production model, accelerator, or learned routing quality. 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 2026-09-30T16:48:37.646348+00:00.

Case digest / e3d7cc884122e94297d9a13b0a2ccb43eb1435d427edb7a869c7a816ae018f0e