=======================================================
                Quantifier Elimination
                          in
            Elementary Algebra and Geometry
                          by
      Partial Cylindrical Algebraic Decomposition

               Version B 1.69, 16 Mar 2012

                          by
                       Hoon Hong
                  (hhong@math.ncsu.edu)

With contributions by: Christopher W. Brown, George E.
Collins, Mark J. Encarnacion, Jeremy R. Johnson
Werner Krandick, Richard Liska, Scott McCallum,
Nicolas Robidoux, and Stanly Steinberg
=======================================================

https://www.usna.edu/CS/qepcadweb/B/QEPCAD.html

This is a (shallow) fork of QEPCAD, a program performing cylindrical algebraic decomposition.

I found the library a bit hard to build (especially with Visual Studio), so I added CMake files which makes the process considerably easier.

Very Simple Example

Given the input

(Ex)[x^2 + a x + b = 0].

the program will output:

An equivalent quantifier-free formula:

4 b - a^2 <= 0

Pretty cool!

There are more examples in the tests folder.

Compiling

With Visual Studio in Windows, everything is included. Just run the CMake graphical interface and point it to the source root.

In Ubuntu, you may have to execute

 sudo apt-get install libreadline-dev 
 

to install a dependency (GNU Readline). Then run

 git clone https://github.com/PetterS/qepcad
 cd qepcad
 mkdir build
 cd build
 cmake ..
 make