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D.5.17.13 ChernClass
Procedure from libraryschubert.lib (see schubert_lib).
- Usage:
- ChernClass(S,i); S sheaf, i int
- Input:
- S is a sheaf, i is a nonnegative integer
- Return:
- poly
- Theory:
- This is the i-th Chern class of a sheaf
LIB "schubert.lib"; variety X; X.dimension = 4; ring r = 0,(c(1..2),d(1..3)),wp(1..2,1..3); setring r; X.baseRing = r; poly c = 1 + c(1) + c(2); poly ch = 2 + logg(c,4); sheaf E = makeSheaf(X,ch); sheaf S = E^3; ChernClass(S,1); ==> 6*c(1) ChernClass(S,2); ==> 11*c(1)^2+10*c(2) ChernClass(S,3); ==> 6*c(1)^3+30*c(1)*c(2) ChernClass(S,4); ==> 18*c(1)^2*c(2)+9*c(2)^2 |