Undecidability and Concatenation
Grzegorczyk Andrzej, Konrad Zdanowski · IOS Press eBooks · 2008
We consider the problem stated by Andrzej Grzegorczyk in “Undecidability without arithmetization” (Studia Logica 79 (2005)) whether certain weak theory of concatenation is essentially undecidable. We give a positive answer for this problem.