SOME PROPERLY HEREDITARY BITOPOLOGICAL PROPERTIES

2021 ◽  
Vol 3 (1) ◽  
pp. 9-15
Author(s):  
B. Alkasasbeh ◽  
H. Hdeib
Keyword(s):  
Separation Axiom ◽  
Hereditary Properties

In this paper we discuss some pairwise properly hereditary properties concerning pairwise separation axiom, and obtain several results related to these properties.

scholarly journals Hereditary properties of semi-separation axioms and their applications

Filomat ◽  
2018 ◽  
Vol 32 (13) ◽  
pp. 4689-4700 ◽  
Author(s):  
Sang-Eon Han
Keyword(s):  
Topological Space ◽  
Infinite Product ◽  
Topological Spaces ◽  
Hereditary Property ◽  
Separation Axiom ◽  
Product Property ◽  
Low Level ◽  
Separation Axioms ◽  
Hereditary Properties

The paper studies the open-hereditary property of semi-separation axioms and applies it to the study of digital topological spaces such as an n-dimensional Khalimsky topological space, a Marcus-Wyse topological space and so on. More precisely, we study various properties of digital topological spaces related to low-level and semi-separation axioms such as T1/2 , semi-T1/2 , semi-T1, semi-T2, etc. Besides, using the finite or the infinite product property of the semi-Ti-separation axiom, i ? {1,2}, we prove that the n-dimensional Khalimsky topological space is a semi-T2-space. After showing that not every subspace of the digital topological spaces satisfies the semi-Ti-separation axiom, i ?{1,2}, we prove that the semi-Tiseparation property is open-hereditary, i ? {1,2}. All spaces in the paper are assumed to be nonempty and connected.

Minimal Characteristic Algebras for Rectangular k-Normal Identities

2011 ◽  
Vol 18 (04) ◽  
pp. 611-628
Author(s):  
K. Hambrook ◽  
S. L. Wismath
Keyword(s):  
Hereditary Property ◽  
Fixed Type ◽  
Hereditary Properties

A characteristic algebra for a hereditary property of identities of a fixed type τ is an algebra [Formula: see text] such that for any variety V of type τ, we have [Formula: see text] if and only if every identity satisfied by V has the property p. This is equivalent to [Formula: see text] being a generator for the variety determined by all identities of type τ which have property p. Płonka has produced minimal (smallest cardinality) characteristic algebras for a number of hereditary properties, including regularity, normality, uniformity, biregularity, right- and leftmost, outermost, and external-compatibility. In this paper, we use a construction of Płonka to study minimal characteristic algebras for the property of rectangular k-normality. In particular, we construct minimal characteristic algebras of type (2) for k-normality and rectangularity for 1 ≤ k ≤ 3.

scholarly journals A new separation axiom in grill topological spaces

2019 ◽  
Vol S (01) ◽  
pp. 706-709
Author(s):  
Maragatha Meenakshi P. ◽  
Chandran S.
Keyword(s):  
Topological Spaces ◽  
Separation Axiom

scholarly journals On Growth Rates of Permutations, Set Partitions, Ordered Graphs and Other Objects

10.37236/799 ◽  
2008 ◽  
Vol 15 (1) ◽  
Author(s):  
Martin Klazar
Keyword(s):  
Growth Rates ◽  
Fibonacci Numbers ◽  
Complete Graphs ◽  
Linear Orders ◽  
Set Partitions ◽  
Ordered Graphs ◽  
Containment Order ◽  
Hereditary Properties ◽  
Finite Linear ◽  
Lower Ideal

For classes ${\cal O}$ of structures on finite linear orders (permutations, ordered graphs etc.) endowed with containment order $\preceq$ (containment of permutations, subgraph relation etc.), we investigate restrictions on the function $f(n)$ counting objects with size $n$ in a lower ideal in $({\cal O},\preceq)$. We present a framework of edge $P$-colored complete graphs $({\cal C}(P),\preceq)$ which includes many of these situations, and we prove for it two such restrictions (jumps in growth): $f(n)$ is eventually constant or $f(n)\ge n$ for all $n\ge 1$; $f(n)\le n^c$ for all $n\ge 1$ for a constant $c>0$ or $f(n)\ge F_n$ for all $n\ge 1$, $F_n$ being the Fibonacci numbers. This generalizes a fragment of a more detailed theorem of Balogh, Bollobás and Morris on hereditary properties of ordered graphs.

scholarly journals Clique-Width and the Speed of Hereditary Properties

10.37236/124 ◽  
2009 ◽  
Vol 16 (1) ◽  
Author(s):  
Peter Allen ◽  
Vadim Lozin ◽  
Michaël Rao
Keyword(s):  
Hereditary Class ◽  
Bell Number ◽  
Hereditary Properties ◽  
The Relationship

In this paper, we study the relationship between the number of $n$-vertex graphs in a hereditary class $\cal X$, also known as the speed of the class $\cal X$, and boundedness of the clique-width in this class. We show that if the speed of $\cal X$ is faster than $n!c^n$ for any $c$, then the clique-width of graphs in $\cal X$ is unbounded, while if the speed does not exceed the Bell number $B_n$, then the clique-width is bounded by a constant. The situation in the range between these two extremes is more complicated. This area contains both classes of bounded and unbounded clique-width. Moreover, we show that classes of graphs of unbounded clique-width may have slower speed than classes where the clique-width is bounded.

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