Singular

LIB "chern.lib";
ring r = 0, (c(1..3)), dp;
list l=c(1..3);
// The Chern numbers of a vector bundle with Chern classes c(1), c(2), c(3)
// on a 3-fold:
print( chNumbers( 3, l ) );
==> [1]:
==>    c(1)^3
==> [2]:
==>    c(1)*c(2)
==> [3]:
==>    c(3)
// If the highest Chern class is zero, the Chern numbers are:
l=c(1..2);
print( chNumbers( 3, l ) );
==> [1]:
==>    c(1)^3
==> [2]:
==>    c(1)*c(2)
==> [3]:
==>    0
// Compare this to the output of chNum(...):
print( chNum( 3, l ) );
==> [1]:
==>    c(1)^3
==> [2]:
==>    c(1)*c(2)