4 results
Thomas Schwentick ; Thomas Zeume.
It is shown that the finite satisfiability problem for two-variable logic over structures with one total preorder relation, its induced successor relation, one linear order relation and some further unary relations is EXPSPACE-complete. Actually, EXPSPACE-completeness already holds for structures […]
Published on March 2, 2012
Thomas Schwentick ; Nicole Schweikardt.
This article shows that there exist two particular linear orders such that first-order logic with these two linear orders has the same expressive power as first-order logic with the Bit-predicate FO(Bit). As a corollary we obtain that there also exists a built-in permutation such that first-order […]
Published on December 14, 2011
Samir Datta ; Anish Mukherjee ; Thomas Schwentick ; Nils Vortmeier ; Thomas Zeume.
In the setting of DynFO, dynamic programs update the stored result of a query whenever the underlying data changes. This update is expressed in terms of first-order logic. We introduce a strategy for constructing dynamic programs that utilises periodic computation of auxiliary data from scratch and […]
Published on May 8, 2019
Gaetano Geck ; Jens Keppeler ; Thomas Schwentick ; Christopher Spinrath.
The paper studies the rewriting problem, that is, the decision problem whether, for a given conjunctive query $Q$ and a set $\mathcal{V}$ of views, there is a conjunctive query $Q'$ over $\mathcal{V}$ that is equivalent to $Q$, for cases where the query, the views, and/or the desired rewriting are […]
Published on November 29, 2023