Checking the version of giac that you are using: version giac

The version (or giac) command returns the version of giac that is running. It doesn’t have any arguments, but it does require parentheses.
Input:

version()

Output:

"giac 1.6.0, (c) B. Parisse and R. De Graeve, Institut Fourier, Universite de Grenoble I"