Mass Problems and Measure-Theoretic Regularity

Autor: Stephen G. Simpson
Rok vydání: 2009
Předmět:
Zdroj: Bull. Symbolic Logic 15, iss. 4 (2009), 385-409
ISSN: 1943-5894
1079-8986
DOI: 10.2178/bsl/1255526079
Popis: A well known fact is that every Lebesgue measurable set is regular, i.e., it includes an Fσ set of the same measure. We analyze this fact from a metamathematical or foundational standpoint. We study a family of Muchnik degrees corresponding to measuretheoretic regularity at all levels of the effective Borel hierarchy. We prove some new results concerning Nies's notion of LR-reducibility. We build some ω-models of RCA0 which are relevant for the reverse mathematics of measure-theoretic regularity.
Databáze: OpenAIRE