A tag system in which a list of n tag rules (each of a special form) is applied to a system in sequential order and then starting again from the first rule. In a cyclic tag system, each set of tag rules has the special structure that a pattern is appended if (and only if) the first element of the current pattern is a 1 and that independent of whether the first element is 0 or 1, the first element is then deleted.

string rewriting system | substitution system | tag system