15-453 Formal Languages, Automata, and Computation
Lecture 18: The Halting Problem
The Halting Problem for Turing machines is the question whether,
given a coding of a Turing machine M and an input word w, M will
halt on input w. We show that the problem is undecidable via
a so-called diagonalization argument. Using this central result
we also demonstrate that there are languages which are not even
This lecture is given by Aleks Nanevski.