We prove that the Gödel incompleteness theorem holds for a weak arithmetic Tₘ = IΔ₀ + Ωₘ, for m ≥ 2, in the form Tₘ ⊬ HCons(Tₘ), where HCons(Tₘ) is an arithmetic formula expressing the consistency of Tₘ with respect to the Herbrand notion of provability. Moreover, we prove , where is HCons relativised to the definable cut Iₘ of (m-2)-times iterated logarithms. The proof is model-theoretic. We also prove a certain non-conservation result for Tₘ.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-fm171-3-7, author = {Zofia Adamowicz}, title = {Herbrand consistency and bounded arithmetic}, journal = {Fundamenta Mathematicae}, volume = {173}, year = {2002}, pages = {279-292}, zbl = {0995.03044}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm171-3-7} }
Zofia Adamowicz. Herbrand consistency and bounded arithmetic. Fundamenta Mathematicae, Tome 173 (2002) pp. 279-292. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm171-3-7/