=ADD=
=reftype=
14
=number=
99-07
=url=
ftp://ftp.risc.uni-linz.ac.at/pub/techreports/1999/99-07.ps.gz
=year=
1999
=month=
03
=author=
Pau; Petru + Schicho; Josef
=title=
Quantifier Elimination for Trigonometric Polynomials by Cylindrical Trigonometric Decomposition
=abstract=
Given a formula $\Phi$ in $r$ variables, some of them quantified
and/or occurring as arguments in trigonometric functions, we 
consider in this paper the problem of finding a quantifier-free 
formula equivalent to $\Phi$.

We present an algorithm that computes first a decomposition of the space 
so that the polynomials occurring in $\Phi$ are sign-invariant over
each cell of this decomposition. Then the cells over which $\Phi$ is
true are collected: their description gives a quantifier-free formula 
equivalent to $\Phi$. The algorithm is an adaption of a well-known 
algorithm for the same problem with polynomial functions.
=sponsor=
FWF project SFB F1303
=end=