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Admit a leader log append: An append attaches to a conflicting predecessor term · case 02

The append log operation is admitted even though an append attaches to a conflicting predecessor term.

Member previewVariant 2 · 3 implementations · 9 checks per implementation

Case contract

Return a Boolean admission decision for admit a leader log append. The record r must satisfy all of: r['leader_term'][0] >= r['leader_term'][1]; r['prefix_exists'][0] <= r['prefix_exists'][1]; r['prefix_term'][0] == r['prefix_term'][1]; r['commit_protected'][0] > r['commit_protected'][1]; r['contiguous_indexes'][1] == list(range(r['contiguous_indexes'][0]+1, r['contiguous_indexes'][0]+1+len(r['contiguous_indexes'][1]))). 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
An append attaches to a conflicting predecessor term	`true`	`false`	Failed

MEMBER ARCHIVE

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