Alasdair Urquhart
contemporaryAnalytic Philosophyb. 1945
Alasdair Urquhart is a Canadian logician and philosopher, Professor Emeritus at the University of Toronto, known for his contributions to relevance logic, the history of logic, and the philosophy of mathematics. He provided the first undecidability proof for the implicational fragment of relevance logic R and has written extensively on Bertrand Russell's logical work.
Notable Achievements
1
Proved the undecidability of the implicational fragments of relevance logics R and E
2
Edited volumes of Bertrand Russell's Collected Papers on logical and philosophical writings
3
Developed semantics for relevance logic using operational frames
4
Contributed foundational work on the complexity of propositional proof systems
5
Advanced scholarship on the history of 20th-century logic