Formal characterization of reduplication

A formal system that unifies reduplication with the rest of (morpho-)phonological processes

In the classical Chomsky Hierarchy, productive total reduplication requires computational power beyond context-free, while other phonological and morphological patterns are regular, or even sub-regular. Existing language classes characterizing reduplicated strings are predicted to generate context-free patterns, such as the palindrome language. This does not match empirical observations. Reduplication, especially total reduplication, is well-attested, yielding various generalizations as the foundation for morphophonological theories. However, the palindrome pattern is not only rare in phonology and morphology, but also relies on conscious reasoning in its computation rather than on implicit linguistic knowledge.

One line of my work extends regular languages to incorporate unbounded copying. I developed a formal framework that unifies reduplication with other morpho-phonological processes by augmenting finite-state automata with queue-like memory storage. Mathematical properties of the resulting language class were further examined. This refinement to the classical Chomsky Hierarchy provides a better match to the language typology without sacrificing mathematical rigor.

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