3. A Big Headed Turing Machine (BHTM) is just like an ordinary Turing machine, but with the ability to read and write two adjacent tape symbols in one step. It moves left or right one cell at each step, as before. a) 15 ptel Explain why BHTMs are no more powerful than ordinary Turing machines. b) [5 ptsl For w E (0,1)*, let SORT(w) be the sorted rearrangement of w, in which all the O's precede the 1's. For example, SORT(10110) = 00111. Explain how a BHTM can compute the SORT function. You don't have to describe your Turing machines completely, but give enough detail that a com petent Turing Machine programmer could implement them