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  1. Path: sparky!uunet!ogicse!usenet.coe.montana.edu!saimiri.primate.wisc.edu!sdd.hp.com!ux1.cso.uiuc.edu!news.cso.uiuc.edu!dan
  2. From: leifj@cyklop.nada.kth.se (Leif Johansson)
  3. Newsgroups: sci.math.research
  4. Subject: A question about extension.
  5. Keywords: extension
  6. Message-ID: <1993Jan27.133806.27456@kth.se>
  7. Date: 27 Jan 93 13:38:06 GMT
  8. Article-I.D.: kth.1993Jan27.133806.27456
  9. Sender: Daniel Grayson <dan@math.uiuc.edu>
  10. Organization: Royal Institute of Technology, Stockholm, Sweden
  11. Lines: 16
  12. Approved: Daniel Grayson <dan@math.uiuc.edu>
  13. Originator: dan@symcom.math.uiuc.edu
  14. X-Submissions-To: sci-math-research@uiuc.edu
  15. X-Administrivia-To: sci-math-research-request@uiuc.edu
  16.  
  17. Consider the following:
  18.  
  19.     0->A->E->B->0
  20.         0->A'->E'->B'->0
  21.         0->E->U->E'->0
  22.  
  23. are three extensions of abelian groups. Is there a way
  24. to express U as a higher ext of something. Are higher
  25. ext's involved in any way ? Any comments and/or hints
  26. would be nice. For various reasons I believe that there
  27. should be an ext^3(something,other) here.
  28.  
  29. Thank you all in advance.
  30. Leif Johansson
  31. Dept of math. University of Stockholm
  32. leifj@matematik.su.se
  33.