David May was my PhD supervisor and always spoke very highly of Sir Tony Hoare.
Edit: I’m also lucky enough to have worked with Geoff Barrett, the guy that completed that formal verification (and went on to do numerous other interesting things). Some people may be interested to learn that this work was the very first formal verification of an FPU - and the famous Intel FPU bug could have been avoided had Intel been using the verification methods that the Inmos and University teams pioneered.
Both of them are legitimately wonderful and intelligent humans that I can only use positive adjectives to describe, but the one I was referring to in this was Jim Woodcock [2]. He had many, many nice things to say about Tony Hoare.
[1] Just so I'm not misleading people, I didn't finish my PhD. No fault at all of the advisor or the school.
I also think his book "Software Engineering Mathematics" [2] is an extremely approachable book for any engineer who wants to learn a bit more theory.
As I said, my dropped PhD is not a failure in any capacity from my advisors or the school, mostly just life juggling stuff.
[1] I don't know why exactly, but of all the places I've been, York has the highest percentage of "genuinely nice" people. It's one of my favorite spots in the UK as a result.
[2] https://a.co/d/02M25LcY, not a referral link.