Rollback

Undoing an applied consolidation: drop what it added, revive what it retired.

Why it matters in a memory layer

An index is reversible by construction — the corpus is untouched, so a bad index is fixed by building another. A memory store has no corpus behind it, so undo is something you design or something you do not have.

It works here for one reason: retirement sets invalid_at and superseded_by on records that stay in the log. Undo is clearing two fields and dropping the added memories, and the store comes back identical — ids, validity, supersession pointers, tiers. A store that had deleted the eight subsumed beliefs could not do this at all, and no amount of care in the rollback function recovers information that is gone.

Undo is a property of the write model, not of the undo function — which is what supersession-not-deletion was buying two levels earlier.

Connections

Taught in: Promotion as a Release

Do not confuse with: Cascade Deletion