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Modules M such that \({\rm {\bf Ext}}_{{\bf \textit{R}}}^{\bf{1}}{({\bf \textit{M}},-)}\) Commutes with Direct Limits


We will use Watts’s theorem together with Lenzing’s characterization of finitely presented modules via commuting properties of the induced tensor functor in order to study commuting properties of covariant Ext-functors.

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Correspondence to Simion Breaz.

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Research supported by the CNCS-UEFISCDI grant PN-II-RU-TE-2011-3-0065.

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Breaz, S. Modules M such that \({\rm {\bf Ext}}_{{\bf \textit{R}}}^{\bf{1}}{({\bf \textit{M}},-)}\) Commutes with Direct Limits. Algebr Represent Theor 16, 1799–1808 (2013).

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  • Ext-functor
  • Direct limit
  • Hereditary ring

Mathematics Subject Classifications (2010)

  • 16E30
  • 16E60
  • 18G15