منابع مشابه
Universal (and Existential) Nulls
Incomplete Information research is quite mature when it comes to so called existential nulls, where an existential null is a value stored in the database, representing an unknown object. For some reason universal nulls, that is, values representing all possible objects, have received almost no attention. We remedy the situation in this paper, by showing that a suitable finite representation mec...
متن کاملExistential and Universal Anchoring 1 Existential and Universal Anchoring : A Case Study
Anchoring constraints were originally proposed for explaining the special faithfulness to edges, both in the domain of Input-Output correspondence (e.g. Benua 1998) and Base-Reduplicant correspondence (e.g. Hendricks 1998). In Optimality Theory framework (Prince & Smolensky 1993), this paper proposes two sets of anchoring constraints, Existential and Universal ANCHORING for edges and head, requ...
متن کاملOn the Universal and Existential Fragments of the µ-Calculus
One source of complexity in the μ-calculus is its ability to specify an unbounded number of switches between universal (AX) and existential (EX) branching modes. We therefore study the problems of satisfiability, validity, model checking, and implication for the universal and existential fragments of the μ-calculus, in which only one branching mode is allowed. The universal fragment is rich eno...
متن کاملCharacterizing Integers among Rational Numbers with a Universal-existential Formula
We prove that Z in definable in Q by a formula with 2 universal quantifiers followed by 7 existential quantifiers. It follows that there is no algorithm for deciding, given an algebraic family of Q-morphisms, whether there exists one that is surjective on rational points. We also give a formula, again with universal quantifiers followed by existential quantifiers, that in any number field defin...
متن کاملImproved Climatic Nulls
Weather and climate prediction rely on inherently different predictors at different time scales. Some of the variability in precipitation on climate time-scales (i.e., interannual) could be attributed to accumulated noise on weather (i.e., daily) time-scales. To determine a lower bound on how much climate variability is due to processes at climate time-scales, weather generator models with no m...
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: Fundamenta Informaticae
سال: 2019
ISSN: 0169-2968,1875-8681
DOI: 10.3233/fi-2019-1819