0 votes 0 votes Consider the problem of determining whether a Turing machine $M$ on an input $w$ ever attempts to move its head left when its head is on the left-most tape cell. 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 302 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.