Finitary Compositions of Two-way Finite-State Transductions

Abstract. The hierarchy of arbitrary compositions of two-way nondeterministic finite-state transductions collapses when restricted to finitary transductions, i.e., transductions that produce a finite set of outputs for each input. The hierarchy collapses to the class of nondeterministic MSO definable transductions, which is inside the second level of that hierarchy. It is decidable whether a composition of two-way nondeterministic finite-state transducers realizes a finitary transduction (i.e., is MSO definable).

• Type: Journal
• Year: 2007
• Where: FUIN
• Authors: Joost Engelfriet, Hendrik Jan Hoogeboom
• Keywords: Arbitrary Compositions, FUIN 2007, MSO Definable Transductions, Nondeterministic finite-state Transductions