ABSTRACT
Some comments on differential graded projective complexes . . . . 224 Monoidality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
9.6 Degreewise n-projective model structures . . . . . . . . . . . . . . . . . . . . . . . 226 Degreewise n-projective complexes over Noetherian rings . . . . . . . 227 Degreewise n-projective complexes over arbitrary rings . . . . . . . . . 233 Monoidality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
9.1 Introduction In this and the next chapter, we will be working mainly with the categories
of left R-modules and complexes over them. These categories are particular examples of a categorical notion known as module over a ringoid, which provides a category-theoretic context to present and prove some results concerning the relation between projective dimensions and model structures.
