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Which computer algebra system allows me to compute the homology of a complex of finitely presented abelian groups which are not necessarily free?

Sage and Magma apparently don't: see here and here.

Edit: I should specify that the main obstacle for me of doing this by hand with a CAS is the lack of an algorithm for computing the kernel of a homomorphism between finitely generated abelian groups.

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    @Jack: Well, I think I cannot use the usual command for the kernel in linear algebra since it will not see the kernel of the projection $\mathbb Z\to\mathbb Z/2$ for instance.2011-01-18

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Magma can compute the kernel and the image of a homomorphism between abelian groups. For instance,

  A<[x]> := AbelianGroup([0]);   B<[y]> := AbelianGroup([2,4]);   C<[z]> := AbelianGroup([2]);   g := hom< B -> C | [z[1],2*z[1]]>;   K := Kernel(g);   K;   f := hom< A -> K | [4*y[1]-2*y[2]]>;   I := Image(f);   I;   K/I; 

gives the following result:

 Abelian Group isomorphic to Z/4  Defined on 1 generator in supergroup B:      K.1 = y[2]  Relations:      4*K.1 = 0  Abelian Group isomorphic to Z/2  Defined on 1 generator in supergroup K:      I.1 = 2*K.1  Relations: 2*I.1 = 0  Abelian Group isomorphic to Z/2  Defined on 1 generator  Relations:      2*$.1 = 0