57 citations · 86 across the 14 of their papers we have counts for
19 papers
When Bi-interpretability implies Synonymy
Harvey M. Friedman, Albert Visser
Two salient notions of sameness of theories are synonymy, also known as definitional equivalence, and bi-interpretability. Of these two definitional equivalence is the strictest no…
Feferman Interpretability
Joost J. Joosten, Luka Mikec, Albert Visser
We introduce a modal logic FIL for Feferman interpretability. In this logic both the provability modality and the interpretability modality can come with a label. This label indica…
Incompleteness of boundedly axiomatizable theories
Ali Enayat, Albert Visser
Our main result (Theorem A) shows the incompleteness of any consistent sequential theory T formulated in a finite language such that T is axiomatized by a collection of sentences o…
Certified -sentences
Taishi Kurahashi, Albert Visser
In this paper, we study the employment of -sentences with certificates, i.e., -sentences where a number of principles is added to ensure that the witness is sufficiently…
Essential Hereditary Undecidability
Albert Visser
In this paper we study \emph{essential hereditary undecidability}. Theories with this property are a convenient tool to prove undecidability of other theories. The paper develops t…
There are no minimal essentially undecidable Theories
Fedor Pakhomov, Juvenal Murwanashyaka, Albert Visser
We show that there is no theory that is minimal with respect to interpretability among recursively enumerable essentially undecidable theories.