
7.5.2.0. bfctOneGB
Procedure from library bfun.lib (see bfun_lib).
 Usage:
 bfctOneGB(f [,s,t]); f a poly, s,t optional ints
 Return:
 list of ideal and intvec
 Purpose:
 computes the roots of the BernsteinSato polynomial b(s) for the
hypersurface defined by f, using only one GB computation
 Assume:
 The basering is commutative and of characteristic 0.
 Background:
 In this proc, the initial Malgrange ideal is computed based on the
algorithm by Masayuki Noro and combined with an elimination ordering.
 Note:
 In the output list, the ideal contains all the roots and the intvec
their multiplicities.
If s<>0, std is used for the GB computation, otherwise,
and by default, slimgb is used.
If t<>0, a matrix ordering is used for GB computations,
otherwise, and by default, a block ordering is used.
 Display:
 If printlevel=1, progress debug messages will be printed,
if printlevel>=2, all the debug messages will be printed.
Example:
 LIB "bfun.lib";
ring r = 0,(x,y),dp;
poly f = x^2+y^3+x*y^2;
bfctOneGB(f);
==> [1]:
==> _[1]=5/6
==> _[2]=1
==> _[3]=7/6
==> [2]:
==> 1,1,1
bfctOneGB(f,1,1);
==> [1]:
==> _[1]=5/6
==> _[2]=1
==> _[3]=7/6
==> [2]:
==> 1,1,1

