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D.15.4.28 chSymm

Procedure from library chern.lib (see chern_lib).

Usage:
chSymm(k, r, c[, pos]); k, r integers, c list of polynomials, pos list of integers

Return:
list with entries: int N, list of polynomials l

Purpose:
computes the rank and the Chern classes of the symmetric power of a vector bundle

Note:
for the second symmetric power chSymm2L(...) could be faster

Example:
 
LIB "chern.lib";
ring r=0, (c(1..5)), dp;
list l=c(1..5);
// the rank and the Chern classes of the second symmetric power of a vector bundle of rank 3
print( chSymm(2, 3, l) );
==> [1]:
==>    6
==> [2]:
==>    [1]:
==>       4*c(1)
==>    [2]:
==>       5*c(1)^2+5*c(2)
==>    [3]:
==>       2*c(1)^3+11*c(1)*c(2)+7*c(3)
==>    [4]:
==>       6*c(1)^2*c(2)+4*c(2)^2+14*c(1)*c(3)
==>    [5]:
==>       4*c(1)*c(2)^2+8*c(1)^2*c(3)+4*c(2)*c(3)
==>    [6]:
==>       8*c(1)*c(2)*c(3)-8*c(3)^2
// the rank and the first 3 Chern classes
// of the second symmetric power of a vector bundle of rank 5
print( chSymm(2, 5, l, 1, 2, 3) );
==> [1]:
==>    15
==> [2]:
==>    [1]:
==>       6*c(1)
==>    [2]:
==>       14*c(1)^2+7*c(2)
==>    [3]:
==>       16*c(1)^3+31*c(1)*c(2)+9*c(3)