A Study of a Positive Fragment of Path Queries: Expressiveness, Normal Form, and Minimization.

Yuqing Wu Dirk Van Gucht Marc Gyssens Jan Paredaens A Study of a Positive Fragment of Path Queries: Expressiveness, Normal Form, and Minimization. 133-145 2009 BNCOD http://dx.doi.org/10.1007/978-3-642-02843-4_14 conf/bncod/2009 db/conf/bncod/bncod2009.html#WuGGP09