Hi,
I am trying to convert a turing machine to oblivious turing machine and I was going through an example but could not understand some part of it.
The situation is such . There exists a K-tape turing machine M, that has been converted in M' a single tape turing machine the example says we can convert this M' to M'' oblivious turing machine accordingly
We really only need to make a few changes to this to make M′ into an oblivious TM M′′:
-When M′ updates the encoding in its right-to-left sweep, it may need to move the ˆ marker to the right. However, M′′ cannot stop and move right when it finds the hat, because it is oblivious. Therefore, the head of M′′ must, on its right-to-left sweep, move LRL every time M′ would move L, so its movement pattern will look like LRLLRLLRL... That way, the head always has the opportunity to move the ˆ marker either left or right when it is encountered.
here ^ represents head of each tape in the initial problem.
I do not understand why M'' cannot move to the right as it is oblivious ?