6 citations · 22 across the 19 of their papers we have counts for
Showing 2014Show all
2 papers · 1 filter
cs.LO2014★ 5 cited
Undecidability of satisfiability in the algebra of finite binary relations with union, composition, and difference
Tony Tan, Jan Van den Bussche, Xiaowang Zhang
We consider expressions built up from binary relation names using the operators union, composition, and set difference. We show that it is undecidable to test whether a given such…
cs.DB2014★ 4 cited
On the satisfiability problem for SPARQL patterns
Xiaowang Zhang, Jan Van den Bussche, François Picalausa
The satisfiability problem for SPARQL patterns is undecidable in general, since the expressive power of SPARQL 1.0 is comparable with that of the relational algebra. The goal of th…