Search results for "property"

Right-Justified Characterization for Generating Regular Pattern Avoiding Permutations

2017

ECO-method and its corresponding succession rules allow to recursively define and construct combinatorial objects. The induced generating trees can be coded by corresponding pattern avoiding permutations. We refine succession rules by using succession functions in case when avoided patterns are regular or c-regular. Although regular patterns are hard to be recognized in general, we give a characterization for its right-justified property which is a prerequisite in the definition of the regular pattern. Based on this characterization, we show the (c-)regularity for various classes of permutations avoiding sets of patterns with variable lengths. Last, the technique of succession functions per…

On the WGSC Property in Some Classes of Groups

2009

The property of quasi-simple filtration (or qsf) for groups has been introduced in literature more than 10 years ago by S. Brick. This is equivalent, for groups, to the weak geometric simple connectivity (or wgsc). The main interest of these notions is that there is still not known whether all finitely presented groups are wgsc (qsf) or not. The present note deals with the wgsc property for solvable groups and generalized FC-groups. Moreover, a relation between the almost-convexity condition and the Tucker property, which is related to the wgsc property, has been considered for 3-manifold groups.

The exact bounds for the degree of commutativity of a p-group of maximal class, I

2002

Abstract The first major study of p-groups of maximal class was made by Blackburn in 1958. He showed that an important invariant of these groups is the ‘degree of commutativity.’ Recently (1995) Fernandez-Alcober proved a best possible inequality for the degree of commutativity in terms of the order of the group. Recent computations for primes up to 43 show that sharper results can be obtained when an additional invariant is considered. A series of conjectures about this for all primes have been recorded in [A. Vera-Lopez et al., preprint]. In this paper, we prove two of these conjectures.

Three Letters from Sophus Lie to Felix Klein on Mathematics in Paris

2018

Sophus Lie and Felix Klein first met in 1869 as students in Berlin. They soon became daily companions and spent the spring of 1870 together in Paris where they met the French mathematicians Michel Chasles, Gaston Darboux, and Camille Jordan. Jordan had just published his classic Traite des substitutions, and the two foreigners read it avidly. Mathematics has not been the same since, for it has often been said – and not altogether unjustly – that from this moment on they made group theory their common property: Lie taking the continuous groups and Klein those that were discontinuous. It should not be overlooked, on the other hand, that this observation was first made by Klein himself in the …

The Equationally-Defined Commutator in Quasivarieties Generated by Two-Element Algebras

2018

The notion of the equationally-defined commutator was introduced and thoroughly investigated in (Czelakowski, 2015). In this work the properties of the equationally-defined commutator in quasivarieties generated by two-element algebras are examined. It is proved: If a quasivariety Q is generated by a finite set of two-element algebras, then the equationally-defined commutator of Q is additive (Theorem 3.1) Moreover it satisfies the associativity law (Theorem 3.6). The second result is strengthened if the quasivariety is generated by a single two-element algebra 2: If Q = SP(2), then the equationally-defined commutator of Q universally validates one of the following laws: [x,y] = x^y or [x,y…

Some Remarks on the Concept of Toleration

1997

The paper contains a conceptual analysis of “act of toleration” and the property of “being tolerant”. Being tolerant is understood as a dispositional property of persons manifested in what the author calls the “circumstances of toleration”. The main circumstances distinguished are: a tendency to prohibit a certain behaviour and the competence to determine the deontic status of the behaviour in question. An act of toleration, then, consists in not prohibiting (or cancelling the prohibition of) that behaviour. It is argued that this requires the existence of two different normative systems, the “basic system”, and the “justifying system”. Acts of toleration must be based on reasons coming fro…

Patents, Competition, and Firms’ Innovation Incentives

2014

This paper presents fresh evidence on the interaction between industrial property rights (patents) and competition, and their joint effect on firms’ innovation. We use panel data of Spanish manufacturing firms for 1990–2006, as well as external information on European Patent Office and US Patent Office patent counts. We construct a new synthetic measure of competition and estimate the impact of patents on this measure at the industry level. Then, the effect of industry-wide competition and patenting on firms’ innovation is estimated at the firm level. Our results suggest that patents reduce the level of competition in the industry, whereas the effect of competition on innovation varies with…

Multilevel preconditioning and adaptive sparse solution of inverse problems

2012

Recursive and bargaining values

2021

Abstract We introduce two families of values for TU-games: the recursive and bargaining values. Bargaining values are obtained as the equilibrium payoffs of the symmetric non-cooperative bargaining game proposed by Hart and Mas-Colell (1996). We show that bargaining values have a recursive structure in their definition, and we call this property recursiveness. All efficient, linear, and symmetric values that satisfy recursiveness are called recursive values. We generalize the notions of potential, and balanced contributions property, to characterize the family of recursive values. Finally, we show that if a time discount factor is considered in the bargaining model, every bargaining value h…

Automatic construction of test sets: Theoretical approach

2005

We consider the problem of automatic construction of complete test set (CTS) from program text. The completeness criterion adopted is C1, i.e., it is necessary to execute all feasible branches of program at least once on the tests of CTS. A simple programming language is introduced with the property that the values used in conditional statements are not arithmetically deformed. For this language the CTS problem is proved to be algorithmically solvable and CTS construction algorithm is obtained. Some generalizations of this language containing counters, stacks or arrays are considered where the CTS problem remains solvable. In conclusion the applications of the obtained results to CTS constr…