Tag
halting-problem
- Sep 19, 2025 Recognizers, Dovetailing, and Complement Asymmetry Why a machine that halts on every yes-instance but may loop on no-instances cannot be closed under complement, and how interleaved simulation converts a recognizer into one for a different set. computation theory
- Dec 9, 2024 Mapping Reductions and the Halting Problem How a computable function that maps one language into another transfers undecidability, why the halting problem follows from acceptance by a reduction in the opposite direction, and where the construction breaks. computation theory