🚀 go-pugleaf

I want to write a computer algebra/theorem proving system, basically
as a learning exercise and a testbed for any new ideas I might have.
I guess, though, that this has been done a million times in the past,
so I want to find out about important existing systems. 

I've done a literature search which has revealed singularly little, so
the next approach is to ask the people on the ground...I don't want to
buy any of the commercial packages - I'm interested in finding out about
the underlying principles.

Can anyone refer me to articles, papers, or even software, from which
I can infer the current wisdom? Also, are there any meetings or
conferences which discuss this sort of thing?

Thanks
Anthony Heading