Issue No. 04 - April (2011 vol. 23)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TKDE.2010.139
Marcelo Arenas , Pontificia Universidad Católica de Chile, Santigo
Claudio Gutierrez , Universidad de Chile, Santiago
Jorge Pérez , Pontificia Universidad Católica de Chile, Santigo
In the paper, “semQA: SPARQL with Idempotent Disjunction” , the authors study the RDF query language SPARQL. In particular, they claim that some of the results presented in  are not correct. In this note, we refute the claims made in , and actually show that some of the formal results of  are incorrect.
RDF, query language, SPARQL, evaluation problem, combined complexity.
J. Pérez, M. Arenas and C. Gutierrez, "Some Remarks on the Paper "semQA: SPARQL with Idempotent Disjunction”," in IEEE Transactions on Knowledge & Data Engineering, vol. 23, no. , pp. 638-639, 2010.