Supplemented and π-Projective Semimodules

CHARACTERIZATIONS OF PROJECTIVE AND k-PROJECTIVE SEMIMODULES

Flat semimodules

To my dearest friend Najla Ali We introduce and investigate flat semimodules and k-flat semimodules. We hope these concepts will have the same importance in semimodule theory as in the theory of rings and modules. 1. Introduction. We introduce the notion of flat and k-flat. In Section 2, we study the structure ensuing from these notions. Proposition 2.4 asserts that V is flat if and only if (V ...

On two generalizations of semi-projective modules: SGQ-projective and $pi$-semi-projective

Let $R$ be a ring and $M$ a right $R$-module with $S=End_R(M)$. A module $M$ is called semi-projective if for any epimorphism $f:Mrightarrow N$, where $N$ is a submodule of $M$, and for any homomorphism $g: Mrightarrow N$, there exists $h:Mrightarrow M$ such that $fh=g$. In this paper, we study SGQ-projective and $pi$-semi-projective modules as two generalizations of semi-projective modules. A ...

Idempotent Subreducts of Semimodules over Commutative Semirings

A short proof of the characterization of idempotent subreducts of semimodules over commutative semirings is presented. It says that an idempotent algebra embeds into a semimodule over a commutative semiring, if and only if it belongs to the variety of Szendrei modes.

On Mode Reducts of Semimodules

Modes are idempotent and entropic algebras. More precisely, an algebra (A,Ω) of type τ : Ω −→ Z is called a mode if it is idempotent and entropic, i.e. each singleton in A is a subalgebra and each operation ω ∈ Ω is actually a homomorphism from an appropriate power of the algebra. Both properties can also be expressed by the following identities: (I) ∀ω ∈ Ω, x . . . xω = x (E) ∀ω, φ ∈ Ω, with m...