from some input data type Y into the initial state of X, and a decoding function ?: X -> Z, converts back from the final state(s) of X into some output data type Z. Once the initial state of X is populated, the X-machine runs to completion, and the outputs are then observed. In general, a machine may deadlock (be blocked), or livelock (never halt), or perform one or more complete computations. For this reason, more recent research has focused on deterministic X-machines, whose behaviour can be controlled and observed more precisely.

Example