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On totally free crossed modules

Published online by Cambridge University Press:  18 May 2009

A. R.-Grandjean
Affiliation:
Departamento de Algebra, Universidad de Santiago, E-15771 Santiago de Compostela, Spain
M. Ladra
Affiliation:
Departamento de Algebra, Universidad de Santiago, E-15771 Santiago de Compostela, Spain
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In [10] we associate to a crossed module (T, G, მ) an invariant abelian crossed module H2(T, G, მ). The construction uses presentations by Set-free crossed modules. Now, Set-free crossed modules are special cases of totally free crossed modules, which are algebraic models of 2-dimensional CW complexes used by several authors (see [1] and [6]). The aim of this paper is to show that H2(T, G, მ) can also be constructed from presentations by arbitrary totally free crossed modules.

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 1998

References

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