scholarly journals Fin-set: A syntactical definition of finite sets

2007 ◽  
pp. 155-163
Author(s):  
Slavisa Presic
Keyword(s):  
Cardinal Number ◽  
Cartesian Product ◽  
Finite Sets ◽  
Finite Set ◽  
Definition Of ◽  
Product Relation

We state Fin-set, by which one founds the notion of finite sets in a syntactical way. Any finite set {a1, a2,..., an} is defined as a well formed term of the form S(a1 + (a2 + (??? + (an?1 + an)???))), where + is a binary and S a unary operational symbol. Related to the operational symbol the term-substitutions (1) are introduced. Definition of finite sets is called syntactical because by two algorithms Set-alg and Calc one can effectively establish whether any given set-terms are equal or not equal. All other notions related to finite sets, like ?, ordered pair, Cartesian product, relation, function, cardinal number are defined as terms as well. Each of these definitions is recursive. For instance, ? is defined by x ? S(a1) iff x = a1 x ? S(a1 + ???+ an) iff x = a1 or x ? S(a2 + ???+ an) x/? ? (? denotes the empty set).

On completely recursively enumerable classes and their key arrays

1956 ◽  
Vol 21 (3) ◽  
pp. 304-308 ◽  
Author(s):  
H. G. Rice
Keyword(s):  
Decision Procedure ◽  
Cardinal Number ◽  
Maximum Amount ◽  
Infinite Class ◽  
Finite Sets ◽  
Amount Of Information ◽  
Recursively Enumerable ◽  
Finite Set ◽  
Partial Recursive Functions ◽  
Set Up

The two results of this paper (a theorem and an example) are applications of a device described in section 1. Our notation is that of [4], with which we assume familiarity. It may be worth while to mention in particular the function Φ(n, x) which recursively enumerates the partial recursive functions of one variable, the Cantor enumerating functions J(x, y), K(x), L(x), and the classes F and Q of r.e. (recursively enumerable) and finite sets respectively.It is possible to “give” a finite set in a way which conveys the maximum amount of information; this may be called “giving explicitly”, and it requires that in addition to an effective enumeration or decision procedure for the set we give its cardinal number. It is sometimes desired to enumerate effectively an infinite class of finite sets, each given explicitly (e.g., [4] p. 360, or Dekker [1] p. 497), and we suggest here a device for doing this.We set up an effective one-to-one correspondence between the finite sets of non-negative integers and these integers themselves: the integer , corresponds to the set αi, = {a1, a2, …, an} and inversely. α0 is the empty set. Clearly i can be effectively computed from the elements of αi and its cardinal number.

Towards a computational theory of social groups: A finite set of cognitive primitives for representing any and all social groups in the context of conflict

2021 ◽  
pp. 1-62
Author(s):  
David Pietraszewski
Keyword(s):  
Social Group ◽  
Group Representation ◽  
Social Groups ◽  
Study Groups ◽  
Human Mind ◽  
Computational Theory ◽  
Mistaken Belief ◽  
Finite Set ◽  
The One ◽  
Definition Of

Abstract We don't yet have adequate theories of what the human mind is representing when it represents a social group. Worse still, many people think we do. This mistaken belief is a consequence of the state of play: Until now, researchers have relied on their own intuitions to link up the concept social group on the one hand, and the results of particular studies or models on the other. While necessary, this reliance on intuition has been purchased at considerable cost. When looked at soberly, existing theories of social groups are either (i) literal, but not remotely adequate (such as models built atop economic games), or (ii) simply metaphorical (typically a subsumption or containment metaphor). Intuition is filling in the gaps of an explicit theory. This paper presents a computational theory of what, literally, a group representation is in the context of conflict: it is the assignment of agents to specific roles within a small number of triadic interaction types. This “mental definition” of a group paves the way for a computational theory of social groups—in that it provides a theory of what exactly the information-processing problem of representing and reasoning about a group is. For psychologists, this paper offers a different way to conceptualize and study groups, and suggests that a non-tautological definition of a social group is possible. For cognitive scientists, this paper provides a computational benchmark against which natural and artificial intelligences can be held.

scholarly journals On minimal log discrepancies and kollár components

2021 ◽  
pp. 1-20
Author(s):  
Joaquín Moraga
Keyword(s):  
Blow Up ◽  
Chain Condition ◽  
Fano Varieties ◽  
Finite Sets ◽  
Fixed Dimension ◽  
Log Canonical ◽  
Finite Set ◽  
Canonical Singularities ◽  
Ascending Chain Condition

Abstract In this article, we prove a local implication of boundedness of Fano varieties. More precisely, we prove that $d$ -dimensional $a$ -log canonical singularities with standard coefficients, which admit an $\epsilon$ -plt blow-up, have minimal log discrepancies belonging to a finite set which only depends on $d,\,a$ and $\epsilon$ . This result gives a natural geometric stratification of the possible mld's in a fixed dimension by finite sets. As an application, we prove the ascending chain condition for minimal log discrepancies of exceptional singularities. We also introduce an invariant for klt singularities related to the total discrepancy of Kollár components.

Fuzzy Measures: A solution to deal with community detection problems for networks with additional information

2020 ◽  
Vol 39 (5) ◽  
pp. 6217-6230
Author(s):  
Inmaculada Gutiérrez ◽  
Daniel Gómez ◽  
Javier Castro ◽  
Rosa Espínola
Keyword(s):  
Community Detection ◽  
Weighted Graph ◽  
Fuzzy Relation ◽  
Fuzzy Measure ◽  
Fuzzy Measures ◽  
Additional Information ◽  
Fuzzy Graphs ◽  
Finite Set ◽  
Definition Of ◽  
Community Detection Problems

In this work we introduce the notion of the weighted graph associated with a fuzzy measure. Having a finite set of elements between which there exists an affinity fuzzy relation, we propose the definition of a group based on that affinity fuzzy relation between the individuals. Then, we propose an algorithm based on the Louvain’s method to deal with community detection problems with additional information independent of the graph. We also provide a particular method to solve community detection problems over extended fuzzy graphs. Finally, we test the performance of our proposal by means of some detailed computational tests calculated in several benchmark models.

scholarly journals On the sum and the difference of finite sets of integers

1976 ◽  
Vol 15 (2) ◽  
pp. 245-251
Author(s):  
Reinhard A. Razen
Keyword(s):  
Finite Sets ◽  
Finite Set ◽  
The Difference

Let A = {ai} be a finite set of integers and let p and m denote the cardinalities of A + A = {ai+aj} and A - A {ai–aj}, respectively. In the paper relations are established between p and m; in particular, if max {ai–ai-1} = 2 those sets are characterized for which p = m holds.

scholarly journals Unicity theorems for meromorphic or entire functions II

1995 ◽  
Vol 52 (2) ◽  
pp. 215-224 ◽  
Author(s):  
Hong-Xun Yi
Keyword(s):  
Meromorphic Functions ◽  
Entire Functions ◽  
Inverse Image ◽  
Finite Sets ◽  
Finite Set ◽  
Special Case

In 1976, Gross posed the question “can one find two (or possibly even one) finite sets Sj (j = 1, 2) such that any two entire functions f and g satisfying Ef(Sj) = Eg(Sj) for j = 1,2 must be identical?”, where Ef(Sj) stands for the inverse image of Sj under f. In this paper, we show that there exists a finite set S with 11 elements such that for any two non-constant meromorphic functions f and g the conditions Ef(S) = Eg(S) and Ef({∞}) = Eg({∞}) imply f ≡ g. As a special case this also answers the question posed by Gross.

scholarly journals On families of finite sets no two of which intersect in a singleton

1977 ◽  
Vol 17 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Peter Frankl
Keyword(s):  
Finite Sets ◽  
Finite Set

Let X be a finite set of cardinality n, and let F be a family of k-subsets of X. In this paper we prove the following conjecture of P. Erdös and V.T. Sós.If n > n0(k), k ≥ 4, then we can find two members F and G in F such that |F ∩ G| = 1.

scholarly journals Finite dimensional characteristics related to superreflexivity of Banach spaces

2004 ◽  
Vol 69 (2) ◽  
pp. 289-295 ◽  
Author(s):  
M. I. Ostrovskii
Keyword(s):  
Banach Spaces ◽  
Normed Space ◽  
Local Theory ◽  
Normed Spaces ◽  
Finite Sets ◽  
Large Cardinality ◽  
Finite Dimensional ◽  
Finite Set

One of the important problems of the local theory of Banach Spaces can be stated in the following way. We consider a condition on finite sets in normed spaces that makes sense for a finite set any cardinality. Suppose that the condition is such that to each set satisfying it there corresponds a constant describing “how well” the set satisfies the condition.The problem is:Suppose that a normed space X has a set of large cardinality satisfying the condition with “poor” constant. Does there exist in X a set of smaller cardinality satisfying the condition with a better constant?In the paper this problem is studied for conditions associated with one of R.C. James's characterisations of superreflexivity.

scholarly journals Counting Derangements, Non Bijective Functions and the Birthday Problem

2010 ◽  
Vol 18 (4) ◽  
pp. 197-200
Author(s):  
Cezary Kaliszyk
Keyword(s):  
Explicit Formula ◽  
Recursive Formula ◽  
Finite Sets ◽  
Birthday Problem ◽  
Finite Set ◽  
One To One

Counting Derangements, Non Bijective Functions and the Birthday Problem The article provides counting derangements of finite sets and counting non bijective functions. We provide a recursive formula for the number of derangements of a finite set, together with an explicit formula involving the number e. We count the number of non-one-to-one functions between to finite sets and perform a computation to give explicitely a formalization of the birthday problem. The article is an extension of [10].

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