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D.15.24.20 addSheaf

Procedure from library schubert.lib (see schubert_lib).

Usage:
addSheaf(A,B); A sheaf, B sheaf

Return:
sheaf

Theory:
This is the direct sum of two sheaves.

Example:
 
LIB "schubert.lib";
variety G = Grassmannian(3,5);
def r = G.baseRing;
setring r;
sheaf S = makeSheaf(G,subBundle);
sheaf Q = makeSheaf(G,quotientBundle);
sheaf D = S + Q;
D;
==> A sheaf of rank  5
==> 
D.ChernCharacter == rankSheaf(D);
==> 1
totalChernClass(D) == 1;
==> 1
See also: dualSheaf; quotSheaf; symmetricPowerSheaf; tensorSheaf.