Same Readout, Different Rollout: When to Let Go

Two histories can reach the same complete state of a modeled system and yield identical, correct model readouts, yet the model predicts different futures under the same actions. We study such pairs after a memory value is deleted or an object returns by a different path. In the tested world-model conditions, every initially correct pair agrees after one action, yet 8.2–16.8% diverge on at least one of three fixed 16-action continuations; at the first split, one branch is usually correct. We test the classical readout-closure requirement on these pairs: an update must preserve the equivalence defined by current answers. Reconstructing a state from those answers restores pair agreement and increases the fraction of world-model pairs whose two branches predict every tested 16-step endpoint correctly. Memory results show why agreement and accuracy remain separate. A structured updater illustrates how identifier-renaming and storage-reordering symmetries can be preserved through future updates. Correct current answers therefore need not make learned states interchangeable for continued computation.