scholarly journals On minimal ordered structures

2005 ◽  
Vol 78 (92) ◽  
pp. 65-72 ◽  
Author(s):  
Predrag Tanovic
Keyword(s):  
Strong Form ◽  
Order Property ◽  
Ordered Structures ◽  
First Order ◽  
Order Structures

We partially describe minimal, first-order structures which have a strong form of the strict order property.

Metaontology

2018 ◽  
Author(s):  
Uriah Kriegel
Keyword(s):  
Second Order ◽  
Order Property ◽  
First Order ◽  
First Approximation

Brentano’s theory of judgment serves as a springboard for his conception of reality, indeed for his ontology. It does so, indirectly, by inspiring a very specific metaontology. To a first approximation, ontology is concerned with what exists, metaontology with what it means to say that something exists. So understood, metaontology has been dominated by three views: (i) existence as a substantive first-order property that some things have and some do not, (ii) existence as a formal first-order property that everything has, and (iii) existence as a second-order property of existents’ distinctive properties. Brentano offers a fourth and completely different approach to existence talk, however, one which falls naturally out of his theory of judgment. The purpose of this chapter is to present and motivate Brentano’s approach.

Logical quantizations of first-order structures

1996 ◽  
Vol 35 (3) ◽  
pp. 495-517 ◽  
Author(s):  
Hirokazu Nishimura
Keyword(s):  
First Order ◽  
Order Structures

Properties of Classes of Random Graphs

1994 ◽  
Vol 3 (4) ◽  
pp. 435-454 ◽  
Author(s):  
Neal Brand ◽  
Steve Jackson
Keyword(s):  
Random Graphs ◽  
Higher Order ◽  
Order Property ◽  
First Order ◽  
New Class ◽  
Vertex Transitive ◽  
Vertex Transitive Graphs ◽  
Almost All ◽  
Transitive Graphs

In [11] it is shown that the theory of almost all graphs is first-order complete. Furthermore, in [3] a collection of first-order axioms are given from which any first-order property or its negation can be deduced. Here we show that almost all Steinhaus graphs satisfy the axioms of almost all graphs and conclude that a first-order property is true for almost all graphs if and only if it is true for almost all Steinhaus graphs. We also show that certain classes of subgraphs of vertex transitive graphs are first-order complete. Finally, we give a new class of higher-order axioms from which it follows that large subgraphs of specified type exist in almost all graphs.

On first-order sentences without finite models

2004 ◽  
Vol 69 (2) ◽  
pp. 329-339 ◽  
Author(s):  
Marko Djordjević
Keyword(s):  
Binary Relation ◽  
Function Symbol ◽  
Complete Theory ◽  
Order Property ◽  
Unary Function ◽  
First Order ◽  
Finite Models

We will mainly be concerned with a result which refutes a stronger variant of a conjecture of Macpherson about finitely axiomatizable ω-categorical theories. Then we prove a result which implies that the ω-categorical stable pseudoplanes of Hrushovski do not have the finite submodel property.Let's call a consistent first-order sentence without finite models an axiom of infinity. Can we somehow describe the axioms of infinity? Two standard examples are:ϕ1: A first-order sentence which expresses that a binary relation < on a nonempty universe is transitive and irreflexive and that for every x there is y such that x < y.ϕ2: A first-order sentence which expresses that there is a unique x such that, (0) for every y, s(y) ≠ x (where s is a unary function symbol),and, for every x, if x does not satisfy (0) then there is a unique y such that s(y) = x.Every complete theory T such that ϕ1 ϵ T has the strict order property (as defined in [10]), since the formula x < y will have the strict order property for T. Let's say that if Ψ is an axiom of infinity and every complete theory T with Ψ ϵ T has the strict order property, then Ψ has the strict order property.Every complete theory T such that ϕ2 ϵ T is not ω-categorical. This is the case because a complete theory T without finite models is ω-categorical if and only if, for every 0 < n < ω, there are only finitely many formulas in the variables x1,…,xn, up to equivalence, in any model of T.

The Predicate of Existence

2019 ◽  
pp. 14-37
Author(s):  
Palle Yourgrau
Keyword(s):  
Bertrand Russell ◽  
Gottlob Frege ◽  
Order Property ◽  
Saul Kripke ◽  
Existential Quantifier ◽  
Modern Logic ◽  
First Order ◽  
David Kaplan ◽  
Theory Of Descriptions ◽  
Nathan Salmon

Kant famously declared that existence is not a (real) predicate. This famous dictum has been seen as echoed in the doctrine of the founders of modern logic, Gottlob Frege and Bertrand Russell, that existence isn’t a first-order property possessed by individuals, but rather a second-order property expressed by the existential quantifier. Russell in 1905 combined this doctrine with his new theory of descriptions and declared the paradox of nonexistence to be resolved without resorting to his earlier distinction between existence and being. In recent years, however, logicians and philosophers like Saul Kripke, David Kaplan, and Nathan Salmon have argued that there is no defensible reason to deny that existence is a property of individuals. Kant’s dictum has also been re-evaluated, the result being that the paradox of nonexistence has not, after all, disappeared. Yet it’s not clear how exactly Kripke et al. propose to resolve the paradox.

scholarly journals Reactive OFF-ON type alkylating agents for higher-ordered structures of nucleic acids

2019 ◽  
Vol 47 (13) ◽  
pp. 6578-6589 ◽  
Author(s):  
Kazumitsu Onizuka ◽  
Madoka E Hazemi ◽  
Norihiro Sato ◽  
Gen-ichiro Tsuji ◽  
Shunya Ishikawa ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Alkylating Agents ◽  
Side Reactions ◽  
Ordered Structures ◽  
Dna And Rna ◽  
G Quadruplex ◽  
Significant Research ◽  
Order Structures ◽  
Ap Site ◽  
Double Strand Dna

Abstract Higher-ordered structure motifs of nucleic acids, such as the G-quadruplex (G-4), mismatched and bulge structures, are significant research targets because these structures are involved in genetic control and diseases. Selective alkylation of these higher-order structures is challenging due to the chemical instability of the alkylating agent and side-reactions with the single- or double-strand DNA and RNA. We now report the reactive OFF-ON type alkylating agents, vinyl-quinazolinone (VQ) precursors with a sulfoxide, thiophenyl or thiomethyl group for the OFF-ON control of the vinyl reactivity. The stable VQ precursors conjugated with aminoacridine, which bind to the G-4 DNA, selectively reacted with a T base on the G-4 DNA in contrast to the single- and double-strand DNA. Additionally, the VQ precursor reacted with the T or U base in the AP-site, G-4 RNA and T-T mismatch structures. These VQ precursors would be a new candidate for the T or U specific alkylation in the higher-ordered structures of nucleic acids.

TYPE-DEFINABILITY, COMPACT LIE GROUPS, AND o-MINIMALITY

2004 ◽  
Vol 04 (02) ◽  
pp. 147-162 ◽  
Author(s):  
ANAND PILLAY
Keyword(s):  
Compact Lie Group ◽  
Compact Lie Groups ◽  
First Order ◽  
Special Cases ◽  
Definable Groups ◽  
Small Index ◽  
Logic Topology ◽  
The Right ◽  
Study Type ◽  
Order Structures

We study type-definable subgroups of small index in definable groups, and the structure on the quotient, in first order structures. We raise some conjectures in the case where the ambient structure is o-minimal. The gist is that in this o-minimal case, any definable group G should have a smallest type-definable subgroup of bounded index, and that the quotient, when equipped with the logic topology, should be a compact Lie group of the "right" dimension. I give positive answers to the conjectures in the special cases when G is 1-dimensional, and when G is definably simple.

Compactly Representing First-Order Structures for Static Analysis

2002 ◽  
pp. 196-212 ◽  
Author(s):  
R. Manevich ◽  
G. Ramalingam ◽  
J. Field ◽  
D. Goyal ◽  
M. Sagiv
Keyword(s):  
Static Analysis ◽  
First Order ◽  
Order Structures

scholarly journals A notion of functional completeness for first-order structure

2005 ◽  
Vol 2005 (14) ◽  
pp. 2207-2215
Author(s):  
Etienne R. Alomo Temgoua ◽  
Marcel Tonga
Keyword(s):  
Order Structure ◽  
Functional Completeness ◽  
First Order ◽  
Term Functions ◽  
Order Structures

Using☆-congruences and implications, Weaver (1993) introduced the concepts of prevariety and quasivariety of first-order structures as generalizations of the corresponding concepts for algebras. The notion of functional completeness on algebras has been defined and characterized by Burris and Sankappanavar (1981), Kaarli and Pixley (2001), Pixley (1996), and Quackenbush (1981). We study the notion of functional completeness with respect to☆-congruences. We extend some results on functionally complete algebras to first-order structuresA=(A;FA;RA)and find conditions for these structures to have a compatible Pixley function which is interpolated by term functions on suitable subsets of the base setA.

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