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7.7.19 nchomolog_lib

Status: experimental
Procedures for Noncommutative Homological Algebra
Viktor Levandovskyy levandov@math.rwth-aachen.de,
Christian Schilli, christian.schilli@rwth-aachen.de,
Gerhard Pfister, pfister@mathematik.uni-kl.de

In this library we present tools of homological algebra for finitely presented modules over GR-algebras.

Procedures: ncExt_R  computes presentation of Ext^k(M',R), M module, R basering, M'=coker(M) ncHom  computes presentation of Hom(M',N'), M,N modules, M'=coker(M), N'=coker(N) coHom  computes presentation of Hom(R^k,A), A matrix over basering R contraHom  computes presentation of Hom(A,R^k), A matrix over basering R dmodoublext  computes presentation of Ext_D^i(Ext_D^i(M,D),D), where D is a basering is_cenBimodule  checks whether a module presented by M is Artin-centralizing is_cenSubbimodule  checks whether a subbimodule M is Artin-centralizing