Forgetting system
The set of mechanisms that suppress, compress, retire, and prune memories to prevent unbounded growth and catastrophic convergence. Operates via severity-stratified suppression, re-consolidation windows, compression into semantic abstractions, and graph pruning.
Forgetting is not a failure mode in the Cognitive Substrate - it is a designed capability. Without active forgetting, the memory substrate grows without bound, retrieval quality degrades as the signal-to-noise ratio falls, and the system risks catastrophic convergence: a cluster of correlated but misleading memories accumulating enough trust score to dominate retrieval. The forgetting system operates through four distinct mechanisms at different severity levels. Suppression is the lightest intervention: a memory's retrieval priority drops to near zero but it remains in the index, recoverable if new evidence rehabilitates it. Re-consolidation is the next level: a flagged memory is replayed through the consolidation pipeline with updated context and emerges either rehabilitated, corrected, or scheduled for retirement. Compression converts a cluster of episodic memories into a single semantic abstraction, preserving the pattern while releasing the storage and retrieval overhead of the originals. Pruning is the final step: memories that have passed through re-consolidation and been found irredeemable are removed from the index and archived to cold storage. Graph pruning removes memory links that have become stale, preventing multi-hop retrieval from following obsolete paths.