We study the edit-distance of regular tree languages. The edit-distance is a metric for measuring the similarity or dissimilarity between two objects, and a regular tree language is a set of trees accepted by a finite-state tree automaton or described by a regular tree grammar. Given two regular tree languages L and R, we define the editdistance d(L,R) between L and R to be the minimum edit-dis...

In recent work, Kobayashi observed that the acceptance by an alternating tree automaton A of an infinite tree T generated by a higher-order recursion scheme G may be formulated as the typability of the recursion scheme G in an appropriate intersection type system associated to the automaton A . The purpose of this article is to establish a clean connection between this line of work and Bucciare...

The fundamental properties of the class QUASI of quasi-relabeling relations are investigated. A quasi-relabeling relation is a tree relation that is de ned by a tree bimorphism (φ,L, ψ), where φ and ψ are quasi-relabeling tree homomorphisms and L is a regular tree language. Such relations admit a canonical representation, which immediately also yields that QUASI is closed under nite union. Howe...

Tree walking transducers are an expressive formalism for reasoning about XSLT-like document transformations. One of the useful properties of tree transducers is decidability of type checking: given a transducer and input and output types, it can be checked statically whether the transducer is type correct, i.e., whether each document adhering to the input type is necessarily transformed into do...

This paper presents a way to verify CCS (without renaming) specifications using tree regular model checking. From a term rewriting system and a tree automaton representing the semantics of CCS and equations of a CCS specification to analyse, an over-approximation of the set of reachable terms is computed from an initial configuration. This set, in the framework of CCS, represents an over-approx...