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Choose a value after prepare responses: A proposer proceeds with too few distinct promises · case 05

The proposal adoption operation is admitted even though a proposer proceeds with too few distinct promises.

Member previewVariant 5 · 3 implementations · 9 checks per implementation

Case contract

Return a Boolean admission decision for choose a value after prepare responses. The record r must satisfy all of: len(set(r['promise_quorum'][0])) >= r['promise_quorum'][1]; r['highest_accepted'][0] == max(r['highest_accepted'][1]); r['accepted_value'][0] == r['accepted_value'][1]; all(x == r['responses_ballot'][0] for x in r['responses_ballot'][1]); len(r['ballot_identity']) == len(set(tuple(x) for x in r['ballot_identity'])). Extra tracing fields are ignored; validation does not mutate the record.

Why this case matters

A deterministic local contract for consensus. Each negative fixture violates exactly one invariant. No transport timing, persistence, cryptographic verification, or full protocol implementation is claimed.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
A proposer proceeds with too few distinct promises	`true`	`false`	Failed

MEMBER ARCHIVE

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