An elementary definability theorem for first order logic
نویسندگان
چکیده
منابع مشابه
A definability theorem for first order logic
In this paper, we will present a definability theorem for first order logic. This theorem is very easy to state, and its proof only uses elementary tools. To explain the theorem, let us first observe that if M is a model of a theory T in a language L, then, clearly, any definable subset S ⊂ M (i.e., a subset S = {a | M |= φ(a)} defined by some formula φ) is invariant under all automorphisms of ...
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ژورنال
عنوان ژورنال: The Journal of Symbolic Logic
سال: 1999
ISSN: 0022-4812,1943-5886
DOI: 10.2307/2586617