This Demonstration shows that it is possible to emulate a register machine using an arithmetic system. From A New Kind of Science, page 673: "The arithmetic system takes the value that it obtains at each step, computes , and then depending on the result applies to one of the arithmetic operations specified by the rule [as shown in the rule icon]. The rule is set up so that if the value of is written in the form then the values of , and on successive steps correspond respectively to the position of the register machine in its program, and to the values of the two registers."