Fact supersession

An AI agent stores facts about a person over time. A fact such as a budget or a deadline can change. When it does, the new value supersedes the old one for the same fact.

The agent should answer with the current value by default. It should still be able to say what was true on an earlier date.

• Old and new values can both sit in memory, so the agent may repeat an outdated fact.
• The system must know which statement is newer, using when the fact happened rather than when it was stored.
• Two statements that cannot both be true need a rule for showing the conflict.

• Memory is dated. A changed value with a newer timestamp becomes the current value, and the earlier value stays answerable by date.
• When two statements cannot both be true, Harny keeps both, picks no winner and returns the conflict as data.

When a changed value arrives with a newer timestamp, it becomes the current value and the earlier value stays answerable by date. Sending the same id again with changed text is different: it creates a new revision, and the memories built on the old revision are deleted.