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2019-09-20 20:56:39 +0200 asked a question Elements of finitely presented module

Hello everyone,

I am computing group homology and have to deal with huge boundary matrices. The result should be a finitely presented Z-module. But I got the following problem

M = Matrix(ZZ,3,[2,1,0,0,0,0,0,0,0])
V = M.left_kernel()
N = Matrix(ZZ,2,[0,2,2,0,0,0])
W = N.image()
Q = V/W

Then I got the warning

 "repr(sage.modules.fg_pid.fgp_module.FGP_Module_class_with_category.element_class at 0x7ff4aad554b0) failed: AttributeError: 'sage.matrix.matrix_integer_sparse.Matrix_integer_sparse' object has no attribute '_clear_denom'

Do you have any idea how I can get through this? I want to know information about the generators of Q.

I can't even ask for its additive order

x = Q.0

Thank you!