Finite languages are those recognized by rewrite grammars whose production rules are all of the form S → w where w belongs to Σ ∗. In other words, every rule rewrites the start symbol “S ” as a word (or sentence) in the language.

This paper presents a computational analysis of metathesis patterns that distinguishes three categories of metathesis that differ in their computational complexity. These categories are local metathesis, bounded long distance metathesis, and unbounded long distance metathesis. Using the formalism of finite state automata, it is established that the first two categories are subsequential, while

This paper first defines the conditions under which copying and deletion processes are subsequential: specifically this is the case when the process is bounded in the right ways. Then, if we analyze metathesis as the composition of copying and deletion, it can be shown that the set of attested metathesis patterns fall into the subsequential or reverse subsequential classes. The implications of bounded copying are extended to partial reduplication, which is also shown to be either subsequential or reverse subsequential. 1