Linearization of definable order relations
نویسندگان
چکیده
منابع مشابه
Linearization of analytic order relations
We prove that if 4 is an analytic partial order then either 4 can be extended to a ∆2 linear order similar to an antichain in 21 ordered lexicographically or a certain Borel partial order ≤0 embeds in 4 . Some corollaries for analytic equivalence relations are given, for instance, if E is a Σ1 1 [z] equivalence relation such that E0 does not embed in E then E is determined by intersections with...
متن کاملOn equivalence relations second order definable over H(κ)
Let κ be an uncountable regular cardinal. Call an equivalence relation on functions from κ into 2 second order definable over H(κ) if there exists a second order sentence φ and a parameter P ⊆ H(κ) such that functions f and g from κ into 2 are equivalent iff the structure 〈H(κ),∈, P, f, g〉 satisfies φ. The possible numbers of equivalence classes of second order definable equivalence relations c...
متن کاملFirst-order definable languages
We give an essentially self-contained presentation of some principal results for first-order definable languages over finite and infinite words. We introduce the notion of a counter-free Büchi automaton; and we relate counter-freeness to aperiodicity and to the notion of very weak alternation. We also show that aperiodicity of a regular ∞-language can be decided in polynomial space, if the lang...
متن کاملDefinable Transversals of Analytic Equivalence Relations
We examine the circumstances under which certain analytic equivalence relations on Polish spaces have definable transversals.
متن کاملOn first-order definable colorings
We address the problem of characterizing H-coloring problems that are first-order definable on a fixed class of relational structures. In this context, we give several characterizations of a homomorphism dualities arising in a class of structure.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Annals of Pure and Applied Logic
سال: 2000
ISSN: 0168-0072
DOI: 10.1016/s0168-0072(99)00013-5