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D.6.1.9 charexp2inter
Procedure from libraryalexpoly.lib (see alexpoly_lib).
- Usage:
- charexp2inter(contact,charexp), contact matrix, charexp list
- Assume:
- charexp contains the integer vectors of characteristic exponents
of the branches of a plane curve singularity, and contact is their
contact matrix
- Return:
- intmat, the matrix intersection multiplicities of the branches
LIB "alexpoly.lib"; ring r=0,(x,y),ds; list INV=invariants((x2-y3)*(x3-y2)*((x2-y3)^2-4x5y-x7)); intmat contact=INV[4][1]; list charexp=INV[1][1],INV[2][1],INV[3][1]; // The intersection matrix is INV[4][2]. print(INV[4][2]); ==> 0 4 8 ==> 4 0 17 ==> 8 17 0 // And it is calculated as ... print(charexp2inter(contact,charexp)); ==> 0 4 8 ==> 4 0 17 ==> 8 17 0 |