Re: A small cartesian closed concrete category
Folk, At Thu, 14 Feb 2008 22:46:44 -0500 Fred E.J. Linton wrote, "... skeletal version of the full category of "sets of cardinality < 2" having as only objects the ordinal numbers 0 and 1." There is a better diagram on carnot now. http://carnot.pathology.ubc.ca/FLcategory.jpg If anyone can point out an error, that will help. There are several ways to specify this in TeX. The _Companion_ mentions LaTeX and two or three packages. Can anyone tell me how to go from TeX to SVG? I've yet to work with SVG. Seems that another approach is to write a macro package for diagrams in SVG and then to code a diagram directly using the macros. Thanks, ... Peter E. -- http://carnot.yi.org/ http://members.shaw.ca/peasthope/
Peter easthope wrote in part:
http://carnot.pathology.ubc.ca/FLcategory.jpg If anyone can point out an error, that will help.
This says that there is a map from 1 to 0. Surely that is a mistake? --Toby
Folk, At Fri, 16 May 2008 00:29:16 -0700 Robert L Knighten wrote, ... no morphism from 1 to 0 -- these are sets after all ... At Fri, 16 May 2008 13:57:40 -0700 Toby Bartels wrote, ... map from 1 to 0. Surely ... a mistake? Right oh, thanks. The diagram is patched. http://carnot.yi.org/FLcategory.jpg Sorry for the poor quality. I kept the file small for sake of anyone using an old modem. How about someone suggesting a name for this category. Seems worth posting as a SVG or PostScript for benefit of other novices such as me. Thanks, ... Peter E. -- http://carnot.yi.org/ http://carnot.pathology.ubc.ca/ http://members.shaw.ca/peasthope/
Is it worth noting, in this jpeg, that the arithmetical
max(1-A, B)
for B^A coincides here with the Boolean
{not}-A or B
for the classical B => A? Cheers, -- Fred ------ Original Message ------ Received: Thu, 22 May 2008 08:54:54 PM EDT From: PETER EASTHOPE <peasthope@shaw.ca> To: categories@mta.ca Subject: categories: Re: A small cartesian closed concrete category
Folk,
At Fri, 16 May 2008 00:29:16 -0700 Robert L Knighten wrote, .. no morphism from 1 to 0 -- these are sets after all ...
At Fri, 16 May 2008 13:57:40 -0700 Toby Bartels wrote, .. map from 1 to 0. Surely ... a mistake?
Right oh, thanks. The diagram is patched. http://carnot.yi.org/FLcategory.jpg
Sorry for the poor quality. I kept the file small for sake of anyone using an old modem.
How about someone suggesting a name for this category. Seems worth posting as a SVG or PostScript for benefit of other novices such as me.
Thanks, ... Peter E.
-- http://carnot.yi.org/ http://carnot.pathology.ubc.ca/ http://members.shaw.ca/peasthope/
participants (3)
-
Fred E.J. Linton -
PETER EASTHOPE -
Toby Bartels