منابع مشابه
Quasi-projective covers of right $S$-acts
In this paper $S$ is a monoid with a left zero and $A_S$ (or $A$) is a unitary right $S$-act. It is shown that a monoid $S$ is right perfect (semiperfect) if and only if every (finitely generated) strongly flat right $S$-act is quasi-projective. Also it is shown that if every right $S$-act has a unique zero element, then the existence of a quasi-projective cover for each right act implies that ...
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Clifford and Preston (1961) showed several important characterizations of right groups. It was shown in Roy and So (1998) that, among topological semigroups, compact right simple or left cancellative semigroups are in fact right groups, and the closure of a right simple subsemigroup of a compact semigroup is always a right subgroup. In this paper, it is shown that such results can be generalize...
متن کاملquasi-projective covers of right $s$-acts
in this paper $s$ is a monoid with a left zero and $a_s$ (or $a$) is a unitary right $s$-act. it is shown that a monoid $s$ is right perfect (semiperfect) if and only if every (finitely generated) strongly flat right $s$-act is quasi-projective. also it is shown that if every right $s$-act has a unique zero element, then the existence of a quasi-projective cover for each right act implies that ...
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In this paper, we consider another generalization for quasi-ideal orthodox transversal, the so-called S0-orthodox transversals. We give a structure theorem for regular semigroups with S0-orthodox transversals. If S0 is a S0-orthodox transversal of S then S can be described in terms of S0. Mathematics Subject Classification: 20M10
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For a measurable space (E,E ), we denote by E+ the set of functions E → [0,∞] that are E → B[0,∞] measurable. It can be proved that if I : E+ → [0,∞] is a function such that (i) f = 0 implies that I(f) = 0, (ii) if f, g ∈ E+ and a, b ≥ 0 then I(af + bg) = aI(f) + bI(g), and (iii) if fn is a sequence in E+ that increases pointwise to an element f of E+ then I(fn) increases to I(f), then there a ...
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ژورنال
عنوان ژورنال: Journal of Pure and Applied Algebra
سال: 2002
ISSN: 0022-4049
DOI: 10.1016/s0022-4049(01)00070-6