HFST: Audit of the API Contracts and Their Relationship with Closure Properties

The purpose of this page is to

  1. collect the well-known closure properties of various classes (ambiguous, non-deterministic, epsilon-containing) of automata and transducers
  2. audit how OpenFST, SFST and our HFST API support and make adequate use of these closure properties.

We anticipate that the current OpenFST and SFST implementations do not use closure properties in the optimal way. For example, there may be operations that assume deterministic input although the nondeterministic automata are, in theory, also closed effectively under the same operation.

Motivation: This survey is an important part of the HFST specification, because we need to specify the contracts for all functions in the HFST API. In addition, we need to ensure that HFST API is posing unnecessary restrictions. Finally, we have to identify areas where further development of HFST and OpenFST is desirable.

-- AnssiYliJyra - 14 Oct 2008
Topic revision: r1 - 2008-10-14 - AnssiYliJyra
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2019 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback