On the Minimal Non-Fregean Grzegorczyk Logic
Joanna Golińska‐Pilarek · Studia Logica · 2015
The paper concerns Grzegorczyk’s non-Fregean logics that are intended to be a formal representation of the equimeaning relation defined on descriptions. We argue that the main Grzegorczyk logics discussed in the literature are too strong and we propose a new logical system, $${\mathsf{MGL}}$$ , which satisfies Grzegorczyk’s fundamental requirements. We present a sound and complete semantics for $${\mathsf{MGL}}$$ and we prove that it is decidable. Finally, we show that many non-classical logics are extensions of $${\mathsf{MGL}}$$ , which makes it a generic non-Fregean logic.