Just a quick question: is it possible to write multiple symbols in succession onto a tape of a Turing Machine at once?
For example, I'm trying to make a Turing machine that will accept the language of all decimal integers that are a multiple of 3. So if the number is 360, I want to write 3 x's onto the tape when it sees 3, and then 6 x's onto the tape when it sees 6...
Is that allowed?
For most definitions of Turing machine, the answer is no. However, it is not hard to show that a machine that allows multiple writes can be simulated by a classical Turing machine.