چكيده فارسي :
In category theory, monomorphisms frequently are too weak
to represent substructures. The notion of regular monomorphism, which
equalizes some parallel pair of morphisms, is usually coincide with natural
subobjects in many categories such as S-posets (posets on which the actions
of a pomonoid S preserve the order).
In this talk, we study some categorical properties of (regular) monomorphisms
in the categories of posets and S-posets. we also characterize all
absolutely retract posets (with respect to all monomorphisms) and then
prove that posets have enough absolutely retracts.
