Epsilon-Removal by Loop Reduction for Finite-state Automata over Complete Semirings
Thomas Hanneforth and Colin de la Higuera
In: FSMNLP 2009, 18-21 Jul 2009, Pretoria, South Africa.
We propose an incremental "-removal algorithm for weighted
finite-state automata. The key idea is that "-cycles are stepwise reduced to "-loops with same source and target state. The weight of these loops can be computed with a closure-operation which requires a complete semiring. Contrary to other approaches, this makes it unnecessary to approximate the contribution of "-cycles to the weight of a path in certain (non k-closed) semirings.