Satisfiability of a Spatial Logic with Tree Variables - Inria - Institut national de recherche en sciences et technologies du numérique Access content directly
Conference Papers Year : 2007

Satisfiability of a Spatial Logic with Tree Variables


We investigate in this paper the spatial logic TQL for querying semi-structured data, represented as unranked ordered trees over an infinite alphabet. This logic consists of usual Boolean connectives, spatial connectives (derived from the constructors of a tree algebra), tree variables and a fixpoint operator for recursion. Motivated by XML-oriented tasks, we investigate the guarded TQL fragment. We prove that for closed formulas this fragment is MSO-complete. In presence of tree variables, this fragment is strictly more expressive than MSO as it allows for tree (dis)equality tests, i.e. testing whether two subtrees are isomorphic or not. We devise a new class of tree automata, called TAGED, which extends tree automata with global equality and disequality constraints. We show that the satisfiability problem for guarded TQL formulas reduces to emptiness of TAGED. Then, we focus on bounded TQL formulas: intuitively, a formula is bounded if for any tree, the number of its positions where a subtree is captured by a variable is bounded. We prove this fragment to correspond with a subclass of TAGED, called bounded TAGED, for which we prove emptiness to be decidable. This implies the decidability of the bounded guarded TQL fragment. Finally, we compare bounded TAGED to a fragment of MSO extended with subtree isomorphism tests.
Fichier principal
Vignette du fichier
tql-csl.pdf (168.08 Ko) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

inria-00148462 , version 1 (08-06-2007)
inria-00148462 , version 2 (12-06-2008)



Emmanuel Filiot, Jean-Marc Talbot, Sophie Tison. Satisfiability of a Spatial Logic with Tree Variables. 16th EACSL Annual Conference on Computer Science and Logic, Sep 2007, Lausanne, Switzerland. pp.130-145, ⟨10.1007/978-3-540-74915-8_13⟩. ⟨inria-00148462v2⟩
294 View
266 Download



Gmail Facebook X LinkedIn More