On (po-)torsion free and principally weakly (po-)flat S-posets

In this paper, we first consider (po-)torsion free and principally weakly (po-)flat S-posets, specifically  we discuss when (po-)torsion freeness implies principal weak (po-)flatness. Furthermore, we give a counterexample to show that Theorem ۳.۲۲ of Shi is incorrect. Thereby we present a correct version of this theorem. Finally, we characterize pomonoids over which all cyclic S-posets are weakly po-flat.

کلیدواژه ها:

Torsion free ، po-torsion free ، principally weakly flat ، pomonoid ، S-poset