关于半模的投射性

On the Projectivity of Semimodules

给出了半模范畴中投射半模的概念 ,讨论了投射半模的若干性质 ,进而证明了一个左R-半模投射的充分必要条件是它是一个自由左R

we define the projective semimodule in the category of semimodules and study some properties of the projective semimodule Furthermore, we prove that a left R-semimodule is projective if and only if it is a retract of a free left R-semimodule