Quoting Steve Vickers <s.j.vickers@cs.bham.ac.uk>:
Toby Bartels wrote:
... Certainly much of what is in the patent application is obvious, but perhaps not all of it; were these diagrams of diagrams a new idea?, or was applying them to computer system specifications a new idea?. ...
Dear Toby,
The idea of treating specifications as colimits is a few decades old now. Burstall and Goguen used it in their categorical account of their specification language Clear, with a specification used to construct a new theory as colimit of others.
Yes, Steve! And they coined also the idea of so-called "based objects" that allow to distinguish between parameter specifications and imported specifications once you are going to develop a fully fledged theory of parametrized specifications. Ingo Classen worked out this in more detail in his PhD thesis around 1995 (?) at Technical University Berlin. Best regards Uwe Wolter [For admin and other information see: http://www.mta.ca/~cat-dist/ ]