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7.7.3.0. checkRoot1
Procedure from library dmod.lib (see dmod_lib).

Usage:
checkRoot1(I,f,alpha [,eng]); ideal I, poly f, number alpha, int eng

Assume:
Basering is D[s], I is the annihilator of f^s in D[s],
that is basering and I are the output of Sannfs-like procedure,
f is a polynomial in K[x] and alpha is a rational number.

Return:
int, 1 if -alpha is a root of the Bernstein-Sato polynomial of f

Purpose:
check, whether alpha is a root of the global Bernstein-Sato polynomial of f

Note:
If eng <>0, std is used for Groebner basis computations,
otherwise (and by default) slimgb is used.

Display:
If printlevel=1, progress debug messages will be printed,
if printlevel>=2, all the debug messages will be printed.

Example:
 
LIB "dmod.lib";
ring r = 0,(x,y),Dp;
poly F = x^4+y^5+x*y^4;
printlevel = 0;
def A = Sannfs(F);
setring A;
poly F = imap(r,F);
checkRoot1(LD,F,31/20);   // -31/20 is not a root of bs
==> 0
checkRoot1(LD,F,11/20);   // -11/20 is a root of bs
==> 1


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