1a. Design a two-track Turing machine that compares two binary strings and decides whether they are equal. If the strings are equal, the machine halts in some fixed state; if they are not equal, the machine halts in some other fixed state.
1b. Solve this same problem using the Turing machine defined in this chapter (regular Turing machine).
1c. Prove the following statement: Any computation that can be carried out using a regular Turing machine can be done using a two-track Turing machine.
1d. On the basis of parts (a) and (b), make an argument for the following statement: Any computation that can be carried out using a two-track Turing machine can be done using a regular Turing machine.