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D.6.11.10 intersection

Procedure from library hnoether.lib (see hnoether_lib).

Usage:
intersection(hne1,hne2); hne1, hne2 lists

Assume:
hne1, hne2 represent an HN expansion of an irreducible plane curve singularity (that is, are the output of develop(f), or of extdevelop(develop(f),n), or one entry of the list of HN data computed by hnexpansion(f[,"ess"])).

Return:
int, the intersection multiplicity of the irreducible plane curve singularities corresponding to hne1 and hne2.

Example:
 
LIB "hnoether.lib";
ring r=0,(x,y),dp;
list Hne=hnexpansion((x2-y3)*(x2+y3));
==> // No change of ring necessary, return value is HN expansion.
intersection(Hne[1],Hne[2]);
==> 6
See also: displayInvariants; hnexpansion.