NOTES ON BOUNDED INDUCTION FOR THE COMPOSITIONAL TRUTH PREDICATE
Bartosz Wcisło, Mateusz Łełyk · The Review of Symbolic Logic · 2017
Abstract We prove that the theory of the extensional compositional truth predicate for the language of arithmetic with Δ0-induction scheme for the truth predicate and the full arithmetical induction scheme is not conservative over Peano Arithmetic. In addition, we show that a slightly modified theory of truth actually proves the global reflection principle over the base theory.