OpenGrm SFst Background Material
The following is provided as background reading about stochastic finite state transducers and related material.
For material on finite state transducers as well as OpenFst, see the compilation
here.
For a presentation of algorithms for weighted automata with failure transitions as used by the operations here, see: Cyril Allauzen and Michael Riley,
"Algorithms for Weighted Automata with Failure Transitions",
Proceedings of the 23rd International Conference on Implementation and Application of Automata, (CIAA 2018), Charloittetown, PEI. Note this paper makes two simplifying assumptions: (1) a successful path can not end in a failure transition and (2) there are no epsilon transitions when failure transitions are present.
Neither limitation is required in this library (failure transitions treat epsilons as defined for a
canonical FST).
Michael Riley - 2018-07-17