A simplification of Girard's paradox

Autor: Antonius J. C. Hurkens
Rok vydání: 1995
Předmět:
Zdroj: Lecture Notes in Computer Science ISBN: 9783540590484
TLCA
DOI: 10.1007/bfb0014058
Popis: In 1972 J.-Y. Girard showed that the Burali-Forti paradox can be formalised in the type system U. In 1991 Th. Coquand formalised another paradox in U−. The corresponding proof terms (that have no normal form) are large. We present a shorter term of type ⊥ in the Pure Type System λU− and analyse its reduction behaviour. The idea is to construct a universe U and two functions such that a certain equality holds. Using this equality, we prove and disprove that a certain object in U is well-founded.
Databáze: OpenAIRE