Singular Manual: mapToRatNormCurve

| #### D.5.11.6 mapToRatNormCurve Procedure from library `paraplanecurves.lib` (see paraplanecurves_lib). Usage: mapToRatNormCurve(f, AI); f polynomial, AI ideal Assume: The polynomial f is homogeneous in three variables and absolutely irreducible. The plane curve C defined by f is rational. The ideal AI is the adjoint ideal of C. Return: ring with an ideal RNC. Example:
    LIB "paraplanecurves.lib";
    ring R = 0,(x,y,z),dp;
    poly f = y^8-x^3*(z+x)^5;
    ideal adj = adjointIdeal(f);
    def Rn = mapToRatNormCurve(f,adj);
    ==> //'mapToRatNorm' created a ring together with an ideal RNC.
    ==> // Supposing you typed, say,  def RPn = mapToRatNorm(f,AI);
    ==> // you may access the ideal by typing
    ==> //      setring RPn; RNC;
    setring(Rn);
    RNC;
    ==> RNC[1]=y(5)*y(6)-y(4)*y(7)
    ==> RNC[2]=y(4)*y(6)-y(3)*y(7)
    ==> RNC[3]=y(2)*y(6)-y(1)*y(7)
    ==> RNC[4]=y(4)*y(5)-y(2)*y(7)
    ==> RNC[5]=y(3)*y(5)-y(1)*y(7)
    ==> RNC[6]=y(1)*y(5)-y(7)^2
    ==> RNC[7]=y(4)^2-y(1)*y(7)
    ==> RNC[8]=y(3)*y(4)-y(1)*y(6)
    ==> RNC[9]=y(2)*y(4)-y(1)*y(5)
    ==> RNC[10]=y(1)*y(4)-y(6)*y(7)
    ==> RNC[11]=y(2)*y(3)-y(6)*y(7)
    ==> RNC[12]=y(1)*y(3)-y(6)^2
    ==> RNC[13]=y(2)^2-y(5)*y(7)
    ==> RNC[14]=y(1)*y(2)-y(4)*y(7)
    ==> RNC[15]=y(1)^2-y(3)*y(7)
    ==> RNC[16]=y(1)*y(6)^2-y(3)^2*y(7)
    ==> RNC[17]=y(6)^4-y(3)^3*y(7)

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