---
name: "giac"
section: "1"
platform: "linux"
package: "xcas"
version: "1.9.0.93+dfsg2-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/giac"
---

# giac(1)

computer algebra system

## NAME

giac - computer algebra system

## SYNOPSIS

**giac** \[*options*\] *files*\
 **icas** \[*options*\] *files*\
 **xcas**  files

## DESCRIPTION

**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/XCAS manual* 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\`.

## OPTIONS

- **--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.

## SEE ALSO

[**cas\_help**(1)](/cas_help/1.md)

## AUTHORS

**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).

## LICENSE

GPLv3+