Can I read The Semijoin Algebra and the Guarded Fragment on EtoBox?

The Semijoin Algebra and the Guarded Fragment by Leinders, Dirk; Tyszkiewicz, Jerzy; Bussche, Jan Van den is a scholarly article available to read on EtoBox.

What is The Semijoin Algebra and the Guarded Fragment about?

The semijoin algebra is the variant of the relational algebra obtained by replacing the join operator by the semijoin operator. We discuss some interesting connections between the semijoin algebra and the guarded fragment of first-order logic. We also provide an Ehrenfeucht-Fraisse game, characterizing the discerning power of the semijoin algebra. This game gives a method for showing that certain queries are not expressible in the semijoin algebra.

Author

Leinders, Dirk; Tyszkiewicz, Jerzy; Bussche, Jan Van den

Published

2004

Language

EN