My three talks at NWPT'01

This page provides the original abstracts for, and access to, drafts of the papers I presented at NWPT'01 (October 2001). A final paper, combining and extending the material in the first two papers given here, appeared as "Algebraic Specifications: some old history and new thoughts" in The Nordic Journal of Computing, Selected papers of the thirteenth Nordic Workshop on Programming Theory (NWPT'01), OCTOBER 10--12, 2001: M. Haveraaen and M. R. Hansen Editors, Vol 9, Number 4, 2002 (373--404).

Algebraic Specifications: Some Old History, and New Thoughts (.PS FILE)


Thirty years ago, in September 1971, the ``ADJ Group'' (Joe Goguen, Jim Thatcher, Eric Wagner, and Jesse Wright) was founded at IBM Research.  In this talk I will sketch the history of the group, and give an overview their technical contributions in the area of data type specification (making considerable use of hindsight).  In brief, my judgment is that we produced a nice, even elegant, theoretical treatment of data type specification, but we, and perhaps those who came after us, failed to produce a workable methodology for developing actual data type and program specifications. I will close with some remarks on my current attempts to find ways to improve this situation.

Investigating Program Specification (.ps file)


In this talk I will present some thoughts on program specification that resulted from using algebraic specification methods to specify some of the programs that I have written in recent years.  The specifications were written after the programs were written and thus might better be described as documentation rather than specifications.  The programs were interactive programs written in Java or JavaScript and up to 800 lines in length.  The algebraic specification methodology is based on the ADJ methodology (conditional axioms, initial algebras and free functors, looser semantics by means of constraints) extended to a form of Moore automata.

Memories of my Early Days with Computers (1951--1954) (on web)


(Dinner Talk)  My involvment with computers began fifty years ago in the Fall of 1951.  In this talk I will relate some of my memories, and show some pictures, from that time.