Gentzen and Ordinal Analysis
Gentzen's consistency proof for arithmetic by transfinite induction up to epsilon-naught, and what it secures
Planned, not yet written
This rung already has its place in the Metalogic ladder and a fixed job in the order. The prose is what is missing. Writing it out of sequence would break the guarantee that nothing here uses a term before an earlier article defines it.
Will defineordinal analysistransfinite inductionepsilon-naughtproof-theoretic ordinal
AssumesHilbert's programmecut eliminationsecond incompleteness theorem