If we view the two states as Boolean values, this correspondence between ordinary and second-order automaton can be described simply: the state of a cell of the second-order automaton at time is the exclusive or of its state at time with the state that the ordinary cellular automaton rule would compute for it. In fact, all two-state second-order rules may be produced in this way. The resulting second-order automaton, however, will generally bear little resemblance to the ordinary CA it was constructed from. Second-order rules constructed in this way are named by Stephen Wolfram by appending an "R" to the number or Wolfram code of the base rule.