Toy transformers may represent belief-state geometry optimally but not minimally

Methods note: The code used for the experiments and related open-source repo were built with Claude. The experimental design and writeup is my own, with minimal editing and formatting amendments made with Claude. Thesis A toy transformer keeps provably predictively defunct belief state data in its residual stream. This information is shed only when there is a sufficient amount of imposed capacity pressure, in which case the oldest predictively defunct information is shed first. Results I conduct...