Thanks, gcd is more complicated than what I think.
Stephen Loo於 2013年7月11日星期四UTC+8下午4時17分45秒寫道：
>
> Hi all,
>
> I found that there are many different kind of gcd in sympy different
> module, such as
>
> sympy.core.numbers.igcd
> sympy.polys.polytools.gcd
> sympy.polys.polytools.gcdex
> sympy.poly
gcdex() handle expression only, no redundant.
Stephen Loo於 2013年7月11日星期四UTC+8下午4時17分45秒寫道：
>
> Hi all,
>
> I found that there are many different kind of gcd in sympy different
> module, such as
>
> sympy.core.numbers.igcd
> sympy.polys.polytools.gcd
> sympy.polys.polytools.gcdex
> sympy.polys.po
