منابع مشابه
Proper Restriction Semigroups – Semidirect Products and W -products
Fountain and Gomes have shown that any proper left ample semigroup embeds into a so-called W -product, which is a subsemigroup of a reverse semidirect product T ⋉ Y of a semilattice Y by a monoid T , where the action of T on Y is injective with images of the action being order ideals of Y. Proper left ample semigroups are proper left restriction, the latter forming a much wider class. The aim o...
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Let n be a positive integer, Pd(n) denotes the product of all positive divisors of n, qd(n) denotes the product of all proper divisors of n. In this paper, we study the properties of the sequences {PdCn)} and {qd(n)}, and prove that the Makowski &. Schinzel conjecture hold for the sequences {pd(n)} and {qd(n)}.
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We determine all the ways in which a direct product of two finite groups can be expressed as the set-theoretical union of proper subgroups in a family of minimal cardinality. Mathematics Subject Classification (2000). 20D60.
متن کاملProper Covers of restriction Semigroups and W-Products
Each factor semigroup of a free restriction (ample) semigroup over a congruence contained in the least cancellative congruence is proved to be embeddable into a W -product of a semilattice by a monoid. Consequently, it is established that each restriction semigroup has a proper (ample) cover embeddable into such a W -product.
متن کاملNo : 5 Title : ‘ Proper Restriction Semigroups – Semidirect Products and W - Products ’ Author ( S )
Fountain and Gomes have shown that any proper left ample semigroup embeds into a so-calledW -product, which is a subsemigroup of a reversed semidirect product T ⋉ Y of a semilattice Y by a monoid T , where the action of T on Y is injective with images of the action being order ideals of Y. Proper left ample semigroups are proper left restriction, the latter forming a much wider class. The aim o...
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ژورنال
عنوان ژورنال: Proceedings of the American Mathematical Society
سال: 2009
ISSN: 0002-9939
DOI: 10.1090/s0002-9939-09-09846-3