On countable chains having decidable monadic theory
Rationals and countable ordinals are important examples of structures with decidable monadic second-order theories. A chain is an expansion of a linear order by monadic predicates. We show that if the monadic second-order theory of a countable chain C is decidable then C has a non-trivial expansion with decidable monadic second-order theory.
Permanent link to this document: http://projecteuclid.org/euclid.jsl/1333566639
Digital Object Identifier: doi:10.2178/jsl/1333566639
Zentralblatt MATH identifier: 06047778
Mathematical Reviews number (MathSciNet): MR2963023