Eric 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]

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

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]