Generalizing Inflection Tables into Paradigms with Finite State Operations

Extracting and performing an alignment of the longest common subsequence in inflection tables has been shown to be a fruitful approach to supervised learning of morphological paradigms. However, finding the longest subsequence common to multiple strings is well known to be an intractable problem. Additional constraints on the solution sought complicate the problem further—such as requiring that the particular subsequence extracted, if there is ambiguity, be one that is best alignable in an inflection table. In this paper we present and discuss the design of a tool that performs the extraction through some advanced techniques in finite state calculus and does so efficiently enough for the practical purposes of inflection table generalization.