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LWW element set with add bias: merge overwrites newer timestamps with older ones · case 05

Merging an older replica state resurrects or hides elements depending on delivery order.

Member previewVariant 5 · 3 implementations · 9 checks per implementation

Case contract

Each replica keeps add and remove timestamp maps. ["add"|"rem", r, e, t] records t when it exceeds the stored timestamp. ["merge", s, d] folds both maps of s into d by maximum. An element is a member when it has an add timestamp that is greater than or equal to its remove timestamp (ties favour add). Return sorted members per replica.

Why this case matters

LWW element sets resolve add/remove races by timestamp and need a deterministic tie bias.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
older merged add does not lower the timestamp	`[[], []]`	`[["z"], []]`	Failed

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