0 votes 0 votes A useless state in a Turing machine is one that is never entered on any input string. Consider the problem of determining whether a Turing machine has any useless states. Formulate this problem as a language and show that it is undecidable. Theory of Computation michael-sipser theory-of-computation turing-machine decidability proof + – admin asked Oct 19, 2019 admin 340 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.