# Singular          ##### 7.5.5.0. SDLoc
Procedure from library `dmodapp.lib` (see dmodapp_lib).

Usage:
SDLoc(I, f); I an ideal, f a poly

Return:
ring (basering extended by a new variable) containing an ideal 'LD'

Purpose:
compute a generic presentation of the localization of D/I w.r.t. f^s

Assume:
the basering D is a Weyl algebra over a field of characteristic 0

Note:
Activate this ring with the `setring` command. In this ring,
the ideal LD (given as Groebner basis) is the presentation of the
localization.

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

Example:
 ```LIB "dmodapp.lib"; ring r = 0,(x,y,Dx,Dy),dp; def R = Weyl(); // Weyl algebra on the variables x,y,Dx,Dy setring R; poly F = x2-y3; ideal I = Dx*F, Dy*F; // note, that I is not holonomic, since it's dimension is not 2 gkdim(I); // 3, while dim R = 4 ==> 3 def W = SDLoc(I,F); setring W; // = R[s], where s is a new variable LD; // Groebner basis of s-parametric presentation ==> LD=3*x*Dx*s+2*y*Dy*s-6*s^2+6*s ==> LD=3*y^2*Dx*s+2*x*Dy*s ==> LD=y^3*Dy-x^2*Dy-3*y^2*s+3*y^2 ==> LD=y^3*Dx-x^2*Dx+2*x*s-2*x ```

### Misc 