Qepcad B

This report introduces Q EPCAD , B, a program for computing with real algebraic sets using cylindrical algebraic decomposition (CAD). QEPCAD B both extends and improves upon the Q EPCAD system for quantifier elimination by partial cylindrical algebraic decomposition written by Hoon Hong in the early 1990s. This paper briefly discusses some of the improvements in the implementation of CAD and quantifier elimination via CAD, and provides somewhat more detail on extensions to the system that go beyond quantifier elimination. The author is responsible for most of the extended features of Q EPCAD B, but improvements to the basic CAD implementation and to the SACLIB library on which Q EPCAD is based are the results of many people's work, including: George E. Collins, Mark J. Encarnación, Hoon Hong, Jeremy Johnson, Werner Krandick, Richard Liska, Scott McCallum, Nicolas Robidoux, and Stanly Steinberg. Source code, documentation and installation instructions for QEPCAD B are all available at www.cs.usna.edu/~qepcad.