1941 – 2023
Peter Aczel (1941–2023) was a British mathematical logician and philosopher of mathematics at the University of Manchester. He made foundational contributions to constructive set theory and non-well-founded set theory, bridging formal logic and the philosophy of mathematics.
Developed non-well-founded set theory, providing a rigorous foundation for circular and self-referential structures
Formulated Constructive Zermelo-Fraenkel (CZF) set theory as a predicative constructive foundation for mathematics
Established the Aczel interpretation, embedding CZF into Martin-Löf dependent type theory
Contributed to the study of inductive and coinductive definitions in formal systems
Applied formal logic to questions in the philosophy of language and identity of abstract objects