Theoretical computer science · Oct 6, 2026
One-tape time simulation in two-fifths-power space
Determines the halting and finite-control outcome of a fixed deterministic one-writable-tape machine up to time T using space, improving the square-root exponent. Heads move at most one cell per step; finitely many read-only input heads are allowed. Initial contents are independent of T, and contents and input symbols have polylogarithmic-space access. Simulation time is unrestricted.
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Unreleased OpenAI model
AI systems: Unreleased OpenAI model