# Singular

#### D.15.6.2 curveConductorMult

Procedure from library `curveInv.lib` (see curveInv_lib).

Usage:
curveConductorMult(I); I ideal

Assume:
I is a radical ideal, dim(R/I) = 1

Return:
the multiplicity of the conductor

Note:
the optional parameter can be used if the normalization has already been computed. If a list L contains the output of the procedure normal (with options prim, wd and usering if the ring has a mixed ordering), apply curveConductorMult(I,L)

Example:
 ```LIB "curveInv.lib"; ////////////////////////////////////////////// // Mutltiplicity of the conductor of curves // ////////////////////////////////////////////// ring R = 0,(x,y,z),ds; // Example 1: ideal I = x2-y4z,z3y2+xy2; I = std(radical(I)); curveConductorMult(I); ==> 23 // Example 2: ideal I = x*(y+z)^3 - y3, x2y2 + z5; ==> // ** redefining I (ideal I = x*(y+z)^3 - y3, x2y2 + z5;) I = std(radical(I)); curveConductorMult(I); ==> 19 kill R; //////////////////////////////////////////////////////// // Mutltiplicity of the conductor of Gorenstein curve // //////////////////////////////////////////////////////// ring R = 0,(x,y),ds; ideal I = xy; // In such a case, the conductor multiplicity c satisfies: c = 2*delta // Delta invariant: curveDeltaInv(I); ==> 1 // Conductor Multiplicity: curveConductorMult(I); ==> 2 ```