In this article, a possible generalization of the Löb’s theorem is considered. Main result is: let κ be an inaccessible cardinal, then ¬Con( ZFC +∃κ) .

We introduce a notion of simplicity for types in discretely ordered first order structures. We prove that all the structure on the locus of a simple type is induced exclusively by the ordering relation. As an application we determine all possible expansions of satisfying CB = 1.

We introduce and study some local versions of o-minimality, requiring that every definable set decomposes as the union of finitely many isolated points and intervals in a suitable neighbourhood of every point. Motivating examples are the expansions of the ordered reals by sine, cosine and other periodic functions.