Fine Hierarchy and Definability in the Lindenbaum Algebra
Victor Selivanov · 1996
Abstract The paper continues an earlier work on applications of a fine hierarchy defined by the author to the classification of index sets. We refine some results relating the fine hierarchy to Boolean terms, prove a useful completeness condition for the levels of the fine hierarchy, discuss a general scheme of the classification of definable index sets, and completely classify index sets of the predicates definable in the Lindenbaum algebra of sentences of any finite rich language.