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D.15.24.13 ChernClass

Procedure from library schubert.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

Example:
 
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
See also: topChernClass; totalChernClass.