Re: diagrams in computer algebra

[Michael J Healy <mjhealy@ece.unm.edu>]

Sergei,

My colleagues and I have been looking for something like this for a project.  We need to be able to specify small categories as the completions of finite graphs we are given, extend these by specifying commutative diagrams, pullbacks, etc, of interest, then define functors generated from graph homomorphisms, and take colimits of diagrams in Cat, etc etc.  We haven't found anything that does all this.  So, we're programming it in Haskell---one of our grad students knows the language.   We'll be happy to share our experience and will probably make the code available.  It's a work in progress.

Best regards,
Mike Healy

On Oct 2, 2011, at 3:10 PM, Sergei SOLOVIEV wrote:

> Question to the list:
> 
> I am very much interested, does there exist any practically usable
> system for the "computer algebra style" work with diagrams. I.e. not
> just write down the diagrams (like XyPic) but for example for
> diagram chasing,
> verification of commutativity in any interesting classes of categories
> with structure etc. As I remember there were some systems permitting
> computation of some limits in very limited classes of categories,
> also some heavy attempts of formalisation in some general
> purpose proof assistants
> but I do not know about anything else.
> 
> Regards to all
> 
> Sergei Soloviev
> 


[For admin and other information see: http://www.mta.ca/~cat-dist/ ]