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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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