Noetherian Godel logics
Abstrakt
We introduce Noetherian Godel logics, Godel logics where the set of truth values is a closed subset of [0,1] containing $0$ and 1 and without any infinite ascending sequences. There are infinitely many such logics, including the well-known logic G(down arrow) whose set of truth values is T-down arrow = {0} boolean OR {1/n : n is an element of N\{0}. We compute the complexity of satisfiability and validity for each Noetherian Godel logic and, in particular, in the logic G(down arrow). This yields optimal strengthening of the results of Baaz-Leitsch-Zach and Hajek.