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).
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.
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
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.
(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.