Discuss the ways in which a Turing machine does or does not satisfy the requirement that an algorithm be a well-ordered collection.

Fill in the blank(s) with the appropriate word(s).

The Turing machine must know which operation to carry out first and which to do next at any step. A Turing machine computation must begin in state 1, reading the leftmost nonblank cell on the tape. In any collection of Turing machine instructions, there cannot be two different instructions that both begin with the same current state and current symbol. Given this requirement, there is never any confusion about which operation to do next. There is at most one instruction that matches the current state and current symbol of the Turing machine. If there is one instruction, the Turing machine executes the operation that instruction describes. If there is no instruction, the Turing machine halts.