Alasdair Urquhart
Encyclopedia
Alasdair Ian Fenton Urquhart, born December 20, 1945, is an emeritus
Professor
of Philosophy
at the University of Toronto
. He has made notable contributions to the field of logic
, especially non-classical logic
. One of his most notable achievements is proving the undecidability
of the relevance logic
R. He also published numerous papers in major theoretical computer science
venues, mostly on mathematical logic
topics of relevance to computer science.
A native of Scotland
, Urquhart received his MA in Philosophy from the University of Edinburgh
in 1967, and his Ph.D.
from the University of Pittsburgh
in 1973 under the supervision of Alan Ross Anderson
and Nuel Belnap
.
Emeritus
Emeritus is a post-positive adjective that is used to designate a retired professor, bishop, or other professional or as a title. The female equivalent emerita is also sometimes used.-History:...
Professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
of Philosophy
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
at the University of Toronto
University of Toronto
The University of Toronto is a public research university in Toronto, Ontario, Canada, situated on the grounds that surround Queen's Park. It was founded by royal charter in 1827 as King's College, the first institution of higher learning in Upper Canada...
. He has made notable contributions to the field of logic
Logic
In philosophy, Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science...
, especially non-classical logic
Non-classical logic
Non-classical logics is the name given to formal systems which differ in a significant way from standard logical systems such as propositional and predicate logic. There are several ways in which this is done, including by way of extensions, deviations, and variations...
. One of his most notable achievements is proving the undecidability
Decidability (logic)
In logic, the term decidable refers to the decision problem, the question of the existence of an effective method for determining membership in a set of formulas. Logical systems such as propositional logic are decidable if membership in their set of logically valid formulas can be effectively...
of the relevance logic
Relevance logic
Relevance logic, also called relevant logic, is a kind of non-classical logic requiring the antecedent and consequent of implications be relevantly related. They may be viewed as a family of substructural or modal logics...
R. He also published numerous papers in major theoretical computer science
Theoretical computer science
Theoretical computer science is a division or subset of general computer science and mathematics which focuses on more abstract or mathematical aspects of computing....
venues, mostly on mathematical logic
Mathematical logic
Mathematical logic is a subfield of mathematics with close connections to foundations of mathematics, theoretical computer science and philosophical logic. The field includes both the mathematical study of logic and the applications of formal logic to other areas of mathematics...
topics of relevance to computer science.
A native of Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, Urquhart received his MA in Philosophy from the University of Edinburgh
University of Edinburgh
The University of Edinburgh, founded in 1583, is a public research university located in Edinburgh, the capital of Scotland, and a UNESCO World Heritage Site. The university is deeply embedded in the fabric of the city, with many of the buildings in the historic Old Town belonging to the university...
in 1967, and his Ph.D.
Ph.D.
A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...
from the University of Pittsburgh
University of Pittsburgh
The University of Pittsburgh, commonly referred to as Pitt, is a state-related research university located in Pittsburgh, Pennsylvania, United States. Founded as Pittsburgh Academy in 1787 on what was then the American frontier, Pitt is one of the oldest continuously chartered institutions of...
in 1973 under the supervision of Alan Ross Anderson
Alan Ross Anderson
Alan Ross Anderson was an American logician and professor of philosophy at Yale University and the University of Pittsburgh....
and Nuel Belnap
Nuel Belnap
Nuel D. Belnap, Jr. is an American logician and philosopher who has made many important contributions to the philosophy of logic, temporal logic, and structural proof theory. He has taught at the University of Pittsburgh since 1961; before that he was at Yale University. His best known work is...
.
Selected publications
- "The Undecidability of Entailment and Relevant Implication." Journal of Symbolic LogicJournal of Symbolic LogicThe Journal of Symbolic Logic is a peer-reviewed mathematics journal published quarterly by Association for Symbolic Logic.Founded in 1936, the journal publishes articles on mathematical logic....
49(4): 1059-1073 (1984). - with Stephen A. Cook, "Functional Interpretations of Feasibly constructive Arithmetic", Annals of Pure and Applied Logic, 1993; preliminary version at STOC'89
- "The Complexity of Decision Procedures in Relevance Logic II", J. Symbolic Logic, Volume 64, Issue 4 (1999), 1774-1802.