• Title/Summary/Keyword: Extension Property

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The annihilators and the hahn-Banach Extension property

  • Park, Sung-Ho
    • Journal of the Korean Mathematical Society
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    • v.31 no.4
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    • pp.691-702
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    • 1994
  • Let X be a normed linear space, M a subspace of X, and V a subspace of the dual space $X^*$. In [3], we studied the Hahn-Banach extension property in V. Here we give the definition and a characterization of the Hahn-Banach extension property in V.

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A MISCELLANY OF SELECTION THEOREMS WITHOUT CONVEXITY

  • Kim, Hoonjoo
    • Honam Mathematical Journal
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    • v.35 no.4
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    • pp.757-764
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    • 2013
  • In this paper, we give sufficient conditions for a map with nonconvex values to have a continuous selection and the selection extension property in LC-metric spaces under the one-point extension property. And we apply it to weakly lower semicontinuous maps and generalize previous results. We also get a continuous selection theorem for almost lower semicontinuous maps with closed sub-admissible values in $\mathbb{R}$-trees.

A RECENT GENERALIZATION OF COFINITELY INJECTIVE MODULES

  • Esra OZTURK SOZEN
    • Honam Mathematical Journal
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    • v.45 no.3
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    • pp.397-409
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    • 2023
  • Let R be an associative ring with identity and M be a left R-module. In this paper, we define modules that have the property (δ-CE) ((δ-CEE)), these are modules that have a δ-supplement (ample δ-supplements) in every cofinite extension which are generalized version of modules that have the properties (CE) and (CEE) introduced in [6] and so a generalization of Zöschinger's modules with the properties (E) and (EE) given in [23]. We investigate various properties of these modules along with examples. In particular we prove these: (1) a module M has the property (δ-CEE) if and only if every submodule of M has the property (δ-CE); (2) direct summands of a module that has the property (δ-CE) also have the property (δ-CE); (3) each factor module of a module that has the property (δ-CE) also has the property (δ-CE) under a special condition; (4) every module with composition series has the property (δ-CE); (5) over a δ-V -ring a module M has the property (δ-CE) if and only if M is cofinitely injective; (6) a ring R is δ-semiperfect if and only if every left R-module has the property (δ-CE).

MIGHTY FILTERS IN BE-ALGEBRAS

  • LEE, HYE RAN;AHN, SUN SHIN
    • Honam Mathematical Journal
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    • v.37 no.2
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    • pp.221-233
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    • 2015
  • The notion of a mighty (vague) filter in a BE-algebra is introduced, and the relation between a (vague) filter and a mighty (vague) filter are given. We investigate an equivalent condition for a (vague) filter to be mighty, and state an extension property for mighty filter. Also we define the notion of an n-fold mighty filter which is an extended notion of a mighty filter in a BE-algebra. Characterizations of an n-fold mighty filter are given. Extension property for an n-fold mighty filter are provided.

POSITIVE IMPLICATIVE MBJ-NEUTROSOPHIC IDEALS IN BCK-ALGEBRAS

  • Roh, Eun Hwan
    • Honam Mathematical Journal
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    • v.44 no.2
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    • pp.209-218
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    • 2022
  • The notion of positive implicative MBJ-neutosophic ideal of BCK-algebras is defined and some properties of it are investigated. Relations between positive implicative MBJ-neutrosophic ideal and positive implicative ideal are discussed. In a BCK-algebra, the extension property for positive implicative MBJ-neutrosophic ideal is established.

INSERTION-OF-FACTORS-PROPERTY WITH FACTORS MAXIMAL IDEALS

  • Jin, Hai-Lan;Jung, Da Woon;Lee, Yang;Ryu, Sung Ju;Sung, Hyo Jin;Yun, Sang Jo
    • Journal of the Korean Mathematical Society
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    • v.52 no.3
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    • pp.649-661
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    • 2015
  • Insertion-of-factors-property, which was introduced by Bell, has a role in the study of various sorts of zero-divisors in noncommutative rings. We in this note consider this property in the case that factors are restricted to maximal ideals. A ring is called IMIP when it satisfies such property. It is shown that the Dorroh extension of A by K is an IMIP ring if and only if A is an IFP ring without identity, where A is a nil algebra over a field K. The structure of an IMIP ring is studied in relation to various kinds of rings which have roles in noncommutative ring theory.