Function: polsturm
Section: polynomials
C-Name: sturmpart
Prototype: lGDGDG
Help: polsturm(pol,{a},{b}): number of real roots of the squarefree polynomial
 pol in the interval ]a,b] (which are respectively taken to be -oo or +oo when
 omitted).
Doc: number of real roots of the real squarefree polynomial \var{pol} in the
 interval $]a,b]$, using Sturm's algorithm. $a$ (resp.~$b$) is taken to be
 $-\infty$ (resp.~$+\infty$) if omitted.
Variant: Also available is \fun{long}{sturm}{GEN pol} (total number of real
 roots).
