

My friend Robert John, professor of computer science at the University of Nottingham, who has died of liver cancer aged 64, pioneered the use of “type-2 fuzzy sets” in computational intelligence, to establish ways of reasoning algorithmically about linguistic concepts that involve uncertainty – something humans are good at, but computers are not.

In the 1990s, while Rob (as he was known to family, though called Bob by work colleagues) was working at De Montfort University, he became involved in research into solving a community transport scheduling problem using fuzzy logic. Working from the foundations laid by Prof Lotfi Zadeh, Rob, through his PhD in 2000 and subsequent work with Prof Jerry Mendel and others, developed the mathematical techniques to use type-2 fuzzy sets. Two papers on type-2 and interval type-2 that he wrote with Mendel are among the most frequently cited and influential in the world on the topic.

Rob was a founder member in 1995 of the Centre for Computational Intelligence at De Montfort and led its growth through the 2000s, established his reputation in the Institute of Electrical and Electronics Engineers’ conferences and in journals on fuzzy logic, and was promoted over time to deputy dean. In 2013 he joined the University of Nottingham as professor of operational research and computer science, and remained there until his diagnosis last year.

Rob was born in Hounslow, Middlesex (now west London), to Veronica (nee Halls), a secretarial supervisor, and David, an insurance claims inspector. They moved to Worthing in West Sussex when he was five. His father was a keen sportsman who introduced Rob to football and cricket, and he continued to play the latter into his 50s.

After A-levels at Worthing technical high school, Rob spent a year on a scholarship in North Carolina in the US. After returning to the UK he studied mathematics at Leicester Polytechnic (now De Montfort University), graduating with a first in 1979. He started training as an actuary, gained an MSc in statistics at the University of Manchester Institute of Science and Technology (Umist) in 1981, then worked in research at British Gas in Fulham, south-west London.

While living in London he met Sylvia Prosser, a patients’ employment officer at Tooting Bec hospital, and they married in 1985 and settled in Tooting. Rob worked in Camberley, Surrey, before setting up his own AI company in the City. Looking for an escape from the stresses of living and working in London, in 1989 Rob started lecturing in mathematics at Leicester Polytechnic. In 1991 he and Sylvia had a son, Gareth. Aged two and a half, Gareth got meningitis, and Rob spent much of his time helping him to develop his strength and hand-eye coordination after the illness.

Rob was passionate about politics and sport: a committed socialist, he supported the miners’ strike and the anti-poll tax campaign. He became a school governor and, following Gareth’s involvement in basketball, coached junior teams in Leicester and Birmingham in the 2000s. He had recently taken up photography.

He is survived by Sylvia and Gareth, and by his brother, Tony.