0 votes 0 votes In the proof of Theorem $5.15$, we modified the Turing machine $M$ so that it never tries to move its head off the left-hand end of the tape. Suppose that we did not make this modification to $M$. Modify the $PCP$ construction to handle this case. Theory of Computation michael-sipser theory-of-computation turing-machine post-correspondence-problem proof + – admin asked Oct 19, 2019 admin 311 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.