4. Assume M is a TM whose program only allows the tape head to move right or stay stationery. (So the tape head on its tape never moves left.) Prove that the language of M is decidable. In particular, give an algorithm which shows that for any input w to M we can decide if M(w) loop or halts. Use this to give an algorithm which decides L(M) = the set of strings w that M accepts. (Hint: To get started think about how many steps the TM can make while staying on the same tape square without repeatin It should be clear that if this repeated state and symbol occurs while M is on the same tape square then M is in a loop.) g the same state and the same symbol on the tape square