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D.5.2.11 chAllInv
Procedure from library chern.lib (see chern_lib).
- Usage:
- chAllInv(l); l a list of polynomials
- Return:
- list of polynomials
- Purpose:
- procedure inverse to chAll(), computes the list of Chern classes
from the list of terms of positive degree of the Chern character
- Note:
- makes sense only for a list of polynomials
Example:
| | LIB "chern.lib";
// first 3 Chern classes in terms of the first 3 terms
// of the Chern character Chern ch(1), ch(2), ch(3):
ring r = 0, (ch(1..3)), dp;
list l=(ch(1..3));
print(chAllInv(l));
==> [1]:
==> ch(1)
==> [2]:
==> 1/2*ch(1)^2-ch(2)
==> [3]:
==> 1/6*ch(1)^3-ch(1)*ch(2)+2*ch(3)
// let's see that chAllInv() is inverse to chAll()
print( chAll( chAllInv(l) ) );
==> [1]:
==> ch(1)
==> [2]:
==> ch(2)
==> [3]:
==> ch(3)
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