Decidability of the Finiteness of Ranges of Tree Transductions

TREE AUTOMATA BASED ON COMPLETE RESIDUATED LATTICE-VALUED LOGIC: REDUCTION ALGORITHM AND DECISION PROBLEMS

In this paper, at first we define the concepts of response function and accessible states of a complete residuated lattice-valued (for simplicity we write $mathcal{L}$-valued) tree automaton with a threshold $c.$ Then, related to these concepts, we prove some lemmas and theorems that are applied in considering some decision problems such as finiteness-value and emptiness-value of recognizable t...

Two-Way Finite State Transducers with Nested Pebbles

Two-way finite state transducers are considered with a fixed number of pebbles, of which the life times are nested. In the deterministic case, the transductions computed by such pebble transducers are closed under composition, and they can be realized by the composition of one-pebble transducers. The ranges of the k-pebble transducers form a hierarchy with respect to k, their finiteness problem...

Decidability and Tameness in the Theory of Finite Semigroups

Internship report - Streaming String Transducers

In formal language theory, two very different models sometimes turn out to describe the same class of languages. This usually shows that there is a fundamental concept described by those models. A well-known example is the class of regular languages, which can be characterized by logic (monadic second order (MSO) logic), algebra (syntactic monoids), and many computational models (automata). In ...

On Equivalence and Uniformisation Problems for Finite Transducers

Transductions are binary relations of finite words. For rational transductions, i.e., transductions defined by finite transducers, the inclusion, equivalence and sequential uniformisation problems are known to be undecidable. In this paper, we investigate stronger variants of inclusion, equivalence and sequential uniformisation, based on a general notion of transducer resynchronisation, and sho...