=ADD= =reftype= 14 =number= 99-04 =url= ftp://ftp.risc.uni-linz.ac.at/pub/techreports/1999/99-04.ps.gz =year= 1999 =month= 01 =author= Schicho; Josef + Tesacek; Antonin =title= An Improved Projection Operator for CAD using Groebner Bases =abstract= In this paper is presented an improvement of projection operator in cylindrical algebraic decomposition (CAD) algorithm, which is very useful algorithm for solving many important mathematical problems involving algebraic constraints. The Groebner bases computation is used in improved projection operator, which yields in smaller projection sets. =sponsor= SFB project 3 =keywords= quantifier elimination