We prove that it is decidable whether a regular unranked tree language is definable in FO2(<h,<v). By FO2(<h,<v. ) we refer to the two variable fragment of ...

May 19, 2015 · By FO2(<h,<v) we refer to the two variable fragment of first order logic built from the descendant relation and the following sibling relation.

Since. FO2(<v,<h) can express the fact that a tree has rank k for any fix number k, our result also applies to ranked trees. Our characterization is stated ...

Abstract. We provide a decidable characterization of regular forest languages definable in FO2(<v, <h). By FO2(<v, <h) we refer to the two variable fragment ...

We prove that it is decidable whether a regular unranked tree language is definable in FO2(<h,<v). By FO2(<h,<v. ) we refer to the two variable fragment of ...

Thomas Place, Luc Segoufin: Deciding definability in FO2(<h, <v) on trees. Log. Methods Comput. Sci. 11(3) (2015). manage site settings.

It is proved that it is decidable whether a regular unranked tree language is definable in FO2(<h,<;v), the two variable fragment of first order logic built ...

Thomas Place ; Luc Segoufin. We provide a decidable characterization of regular forest languages definable in FO2(<h,<v). By FO2(<h,<v) we refer to ...