Bernard Parisse
Institut Fourier, Université Grenoble-Alpes


I'm working in Grenoble since 1992. My initial research domain was mathematical physics. I started programming small programs on HP48 calculators, it became later popular and my colleague Renée De Graeve contacted HP. I worked with HP one year on the HP49G CAS (the same CAS was later available on the HP40G, 40GS, 49G+ and 50G).
In year 2000, I started with Renée a free computer algebra system programmed in C++, named Giac/Xcas, Giac is the computing kernel, Xcas is one of its interfaces I maintain myself. Giac can be used in several contexts: from embedded systems in calculators (minimal requirements: 2Mo of ROM and 128K of RAM) to big computations of Groebner basis on servers with 80 threads in parallel. It is used by projects like Geogebra, the HP Prime calculator CAS, the PocketCAS software for iPhone/iPad/Mac, also ported to other calculator manufacturers, like the Casio Prizm family or the TI Nspire CX and CX2. It is used internally by the Goodnotes app to check some maths while student are training for tests. It is available as a standard package on most Linux distributions, and is also a standard package for SageMath.

Computer algebra system

Giac/xcas, a free computer algebra system

Giac/Xcas is a free computer algebra system for Windows, Mac OS X and Linux/Unix (license GPL3). It has a compatibility mode for maple, mupad and the TI89. It is available as a standalone program (graphic or text interfaces) or as a C++ library. It's name is derived from GiNaC and means Giac Is A Computer algebra system.

CAS e-prints

HP Prime

Giac/Xcas is the native CAS of the HP Prime calculator and Android, iOS, Windows/Mac applications emulating the HP Prime. Press the CAS key and try Xcas commands, most of them work unchanged Documentation by Renée De Graeve, translated by J.M. Lecointre.

Old HP Calculators

I'm the main author of the CAS of the HP49G, HP40G, HP49G+ and HP48GII calculators. I have also developped in 2005 an interactive and analytic geometry module.

HP CAS documentation

HP49G, HP49G+, HP48GII, HP50G documentation

CAS documentation for all ROM versions PDF or LaTeX, by Renée De Graeve , translated by Ivan Cibrario Bertolotti

HP40G/GS CAS documentation

HP49G CAS source code

The source code of my contribution to the HP49G CAS is released under the LGPL license of the Free Software Foundation. If you want to modify the CAS on your calculator, please get the file, unzip it, and follow the instructions in the file CASrelease/README. Warning, the file is not released under the LGPL license and may not be redistributed as is. The files subject to the LGPL license are all the files contained in the CASrelease/ROM/CAS and CASrelease/ROM/CAS2 directories except files containing ALG48 code, namely CAS/berle.s*, CAS/binary.s*, CAS/distdiv.s*, CAS/error.s*, CAS/errors.s*, CAS/grobner.s*, CAS/mkpoly.s*, CAS/pfctr.s*, CAS/prime.s*, CAS/qarth.s*, CAS/root.s*, CAS/smod.s*, CAS/util.s*, CAS/zckconv.s*, CAS/zcmp.s*, CAS/znext.s*, CAS/zpush.s*, CAS/zsutil.s*, CAS/ztests.s*, CAS2/asmgamma.s*, CAS2/asmpsi.s*, CAS2/numgamma.s*, CAS2/numpsi.s*, CAS2/qpi.s*, CAS2/symgamma.s*, CAS2/sympsi.s*, CAS2/util.s*, CAS2/zfact.s*

HP49/50 Interative Geometry

To be used in conjunction with the CASrelease above. This application is released under the GPL license (for dual-licensing contact the author):

Mathematical physics



Construction BKW en fonds de puits, cas particuliers (Dirac, Schrodinger avec champ magnétique) : PDF format or LaTeX source

Lecture notes

Cours de gémétrie différentielle et symplectique , course of the Ecole d'été sur les D-modules (Institut Fourier, Grenoble, June 1995), available as on-line HTML, postscript or tar-gzipped html
Introduction à l'opérateur de Dirac lecture given at the Groupe de travail quantique à (Grenoble, March 1997), available as on-line HTML , postscript or tar-gzipped html Note that other documents are available from my French homepage.

Bernard Parisse, Institut Fourier (CNRS UMR 5582), 100 rue des Maths, Université Grenoble Alpes, CS 40700, 38058 Grenoble cedex 9
You can send me a mail to bernard.parisse at univ-grenoble-alpes dot fr
Design inspired by Elie Carrot, Eliott Dokenoo and Zexi Ru work on Xcas web pages.