Abstract
Axiom systems are ubiquitous in mathematical logic, one famous example being first order Peano Arithmetic. Foundational questions asked about axiom systems comprise analysing their provable consequences, describing their class of provable recursive functions (i.e. for which programs can termination be proven from the axioms), and characterising their consistency strength. One branch of proof theory, called Ordinal Analysis, has been quite successful in giving answers to such questions, often providing a unifying approach to them. The main aim of Ordinal Analysis is to reduce such questions to the computation of so called proof theoretic ordinals, which can be viewed as abstract measures of the complexity inherent in axiom systems. Gentzen’s famous consistency proof of arithmetic [Gen35, Gen38] using transfinite induction up to (a notation of) Cantor’s ordinal ε 0, can be viewed as the first computation of the proof theoretic ordinal of Peano Arithmetic.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
