Eric Hehner

Eric C. R. Hehner
Born	(1947-09-16) September 16, 1947 (age 78) Ottawa, Ontario, Canada
Education	Carleton University (B.Sc., 1969) University of Toronto (M.Sc., 1970; Ph.D., 1974)
Known for	Predicative programming Formal methods Quote notation ALGOL
Scientific career
Fields	Computer science Programming
Institutions	University of Toronto
Website	www.cs.toronto.edu/~hehner

Eric "Rick" C. R. Hehner (born 16 September 1947) is a Canadian computer scientist. He was born in Ottawa. He studied mathematics and physics at Carleton University, graduating with a Bachelor of Science (B.Sc.) in 1969. He studied computer science at the University of Toronto, graduating with a Master of Science (M.Sc.) in 1970, and a Doctor of Philosophy (Ph.D.) in 1974. He then joined the faculty there, becoming a full professor in 1983. He became the Bell University Chair in software engineering in 2001, and retired in 2012.^[1]

Hehner's main research area is formal methods of software design. His method, initially called predicative programming, later called Practical Theory of Programming, is to consider each specification to be a binary (boolean) expression, and each programming construct to be a binary expression specifying the effect of executing the programming construct. Refinement is just implication. This is the simplest formal method, and the most general, applying to sequential, parallel, stand-alone, communicating, terminating, nonterminating, natural-time, real-time, deterministic, and probabilistic programs, and includes time and space bounds. This idea has influenced other computer science researchers, including Tony Hoare.^{[citation needed]}

Hehner's other research areas include probabilistic programming, unified algebra, and high-level circuit design. In 1979, Hehner invented a generalization of radix complement called quote notation, which is a representation of the rational numbers that allows easier arithmetic and precludes roundoff error.^{[citation needed]}

He was involved with developing international standards in programming and informatics, as a member of the International Federation for Information Processing (IFIP) IFIP Working Group 2.1 on Algorithmic Languages and Calculi,^[1][2] which specified, maintains, and supports the programming languages ALGOL 60 and ALGOL 68.^[3] and of IFIP Working Group 2.3 on Programming Methodology.^[1]

References

1. Hehner, Eric C. R. (3 May 2020). "Eric C. R. Hehner". Department of Computer Science. University of Toronto. Retrieved 2020-07-27.
2. Jeuring, Johan; Meertens, Lambert; Guttmann, Walter (2016-08-17). "Profile of IFIP Working Group 2.1". Foswiki. Retrieved 2020-10-16.
3. Swierstra, Doaitse; Gibbons, Jeremy; Meertens, Lambert (2011-03-02). "ScopeEtc: IFIP21: Foswiki". Foswiki. Retrieved 2020-10-16.

• Hehner, E. C. R. (1984). "Predicative Programming". Communications of the ACM. 27 (2): 134–151. doi:10.1145/69610.357988. S2CID 11577076.
• Hehner, E. C. R. (1990). "A Practical Theory of Programming". Science of Computer Programming. 14 (2–3): 133–158. doi:10.1016/0167-6423(90)90018-9.
• Hehner, E. C. R. (2004). "From Boolean Algebra to Unified Algebra". Mathematical Intelligencer. 26 (2): 3–19. CiteSeerX 10.1.1.638.1782. doi:10.1007/BF02985647. S2CID 61678587.
• Hehner, E. C. R.; Horspool, R.N.S. "A new representation of the rational numbers for fast easy arithmetic" (PDF). {{cite journal}}: Cite journal requires |journal= (help)

External links

• Official website
• DBLP publications
• A Practical Theory of Programming, Professor Hehner's book, available free in PDF
• Eric Hehner archival papers held at the University of Toronto Archives and Records Management Services