From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/1929 Path: news.gmane.org!not-for-mail From: Per Newsgroups: gmane.science.mathematics.categories Subject: Extension of natural transformations Date: Fri, 27 Apr 2001 08:48:14 +0200 Message-ID: <3AE9162E.7030606@math.uit.no> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1241018210 1240 80.91.229.2 (29 Apr 2009 15:16:50 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 15:16:50 +0000 (UTC) To: categories@mta.ca Original-X-From: rrosebru@mta.ca Fri Apr 27 09:54:22 2001 -0300 Return-Path: Original-Received: (from Majordom@localhost) by mailserv.mta.ca (8.11.1/8.11.1) id f3RBrPs09426 for categories-list; Fri, 27 Apr 2001 08:53:25 -0300 (ADT) X-Authentication-Warning: mailserv.mta.ca: Majordom set sender to cat-dist@mta.ca using -f User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; m18) Gecko/20001108 Netscape6/6.0 X-Accept-Language: en Original-Sender: cat-dist@mta.ca Precedence: bulk X-Keywords: X-UID: 27 Original-Lines: 14 Xref: news.gmane.org gmane.science.mathematics.categories:1929 Archived-At: Is there anything known about the following type of problem. Let F,G : C -> D be functors and let E be a subcategory of C and let F' G' be the restirctions of F and G to E. Let a' : F' -> G' be a natural transformation. When does there exist a natural transformation alpha : F -> G that extends alpha' so that alpha restricted to E is equal to alpha'? What if E is a set of generators for C? Thanks Per K. Jakobsen