giac - computer algebra system

giac is written by Bernard Parisse.  https://www-fourier.ujf-grenoble.fr/~parisse/giac.html

       This   manual   page   was   written  by  Carleos  Artime  <carleos@pinon.ccu.uniovi.es>  and  Ximin  Luo
       <infinity0@debian.org> for the Debian GNU/Linux system (but may be used by others).

giac  is an advanced symbolic and numeric calculator. The console interface is named icas or equivalently
       giac. The corresponding GUI program is called xcas.

       These programs have extensive documentation. The GIAC/XCASmanual is available in Info format by invoking
       `info giac`, and in HTML and DVI format in /usr/share/giac/doc. One can also obtain  some  help  about  a
       keyword like this, from inside the program:

          0>> ?gcd
          Returns the greatest common divisor of 2 polynomials of several variables
          or of 2 integers or of 2 rationals.
          (Intg(a) or Poly),(Intg(b) or Poly)
          gcd(45,75); gcd(15/7,50/9); gcd(x^2-2*x+1,x^3-1); gcd(t^2-2*t+1,t^2+t-2);
          gcd((x^2-1)*(y^2-1)*z^2,x^3*y^3*z+(-(y^3))*z+x^3*z-z)
          lcm,euler,modgcd,ezgcd,psrgcd,heugcd,Gcd

       The equivalent output may be retrieved by invoking (e.g.) `cas_help gcd`.

       GPLv3+

                                                   2017-02-08                                            GIAC(1)

       giac - computer algebra system

--version
              Show version of program.

       --texmacs
              To call giac/icas from inside Texmacs. Users should not need to do this.

       --emacs
              To call giac/icas from inside Emacs. Users should not need to do this.

       --sage To call giac/icas from inside Sage. Users should not need to do this.

cas_help(1)

giac [options] filesicas [options] filesxcas  files