Retraction is not deletion: what happens when an agent memory deletes a source
Agent-memory products ship add/update/delete as if memory were a CRUD store. But a memory that derives has downstream state resting on what it deletes, and one delete destroys both the record of what was believed and the means of finding what depended on it. What that costs, what Graphiti already fixes, and the two rules a store needs instead: every reference resolves at the commit it was written on, and a retraction may assert falsehood but never that history should leave the corpus.