| Popis: |
We expose a pattern for establishing Friedman-Weiermann style independence results according to which there are thresholds of prov- ability of some parameterized variants of well-partial-ordering. For this purpose, we investigate an ordinal notation system for #!, the small Ve- blen ordinal, which is the proof-theoretic ordinal of the theory (�1 -BI)0. We also show that it sometimes suffices to prove the independence w.r.t. PA in order to obtain the same kind of independence results w.r.t. a stronger theory such as (� 1 -BI)0. |
