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7.7.4.0. Sannfslog
Procedure from library dmod.lib (see dmod_lib).
- Usage:
- Sannfslog(f [,eng]); f a poly, eng an optional int
- Return:
- ring
- Purpose:
- compute the D-module structure of basering[1/f]*f^s
- Note:
- activate the output ring with the
setring command.
In the output ring D[s], the ideal LD1 is generated by the elements
in Ann F^s in D[s], coming from logarithmic derivations.
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 = x4+y5+x*y4;
printlevel = 0;
def A = Sannfslog(F);
setring A;
LD1;
==> LD1[1]=4*x^2*Dx+5*x*y*Dx+3*x*y*Dy+4*y^2*Dy-16*x*s-20*y*s
==> LD1[2]=16*x*y^2*Dx+4*y^3*Dx+12*y^3*Dy-125*x*y*Dx-4*x^2*Dy+5*x*y*Dy-100*y^\
2*Dy-64*y^2*s+500*y*s
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