There seem to be two definitions of what a saturated class should be:
- A class of morphisms closed under retracts, pushouts and transfinite composition.
- A class of monomorphisms containing all isomomorphisms, closed under retracts, pushouts, arbitrary coproducts and countable composition.
My question is, does it make a difference which definition one choses in the context of the cofibrantly generated modelstructures on
- $\mathbf{Top}$, with respect to the Quillen model structure
- $\mathbf{sSet}$, with respect to the Quillen (or Kan) Model structure
- $\mathbf{Cat}$, with respect to the Thomason model structure