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last edited 16 years ago by japp |
Edit detail for #343 Bug in FreeAbelianGroup revision 5 of 5
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Editor: japp
Time: 2008/10/16 11:21:36 GMT-7 |
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changed: - -From japp Thu Oct 16 11:09:05 -0700 2008 -From: japp -Date: Thu, 16 Oct 2008 11:09:05 -0700 -Subject: -Message-ID: <20081016110905-0700@axiom-wiki.newsynthesis.org> - -Status: fix proposed => fixed somewhere - - -From japp Thu Oct 16 11:21:13 -0700 2008 -From: japp -Date: Thu, 16 Oct 2008 11:21:13 -0700 -Subject: -Message-ID: <20081016112113-0700@axiom-wiki.newsynthesis.org> - -Status: fixed somewhere => fix proposed -
The order in FreeAbelianGroup is broken and makes the domain unusable
(e.g., comparison of Set FreeAbelianGroup S does not work properly)
For example here is a cycle:
---------------------------------------- Z2:=FreeAbelianGroup Symbol a:= a::FreeAbelianGroup Symbol b:= b::FreeAbelianGroup Symbol z:= 0::FreeAbelianGroup Symbol a < -b -b < z z < a ----------------------------------------
thus 
fricas
(1) -> a:= a::FreeAbelianGroup Symbol
There are no library operations named FreeAbelianGroup Use HyperDoc Browse or issue )what op FreeAbelianGroup to learn if there is any operation containing " FreeAbelianGroup " in its name.
Cannot find a definition or applicable library operation named FreeAbelianGroup with argument type(s) Type
Perhaps you should use "@" to indicate the required return type,or "$" to specify which version of the function you need.
proposed patch in the last few lines of free.spad:
545,546c545,546 < ta.gen < tb.gen => true < ta.gen > tb.gen => false --- > ta.gen < tb.gen => tb.exp > 0 > ta.gen > tb.gen => ta.exp < 0
apparently revlex order is intended but is not achieved in the current implementation, as the sign of the trailing exponent is not taken into account.
Fixed in wh-sandbox Revision: 496 --kratt6, Mon, 09 Apr 2007 13:50:56 -0500 reply
Status: open => fix proposed
Fixed in OpenAxiom