… An investigation of these TTF classes yields characterizations of various … ) BP is projective
(flat) and (2) AT is projective (flat). The concept of weak stability for a hereditary torsion class is …

… Then c is a torsion class. Similarly, if we define cr to be the class of those left R-modules Y
for which Hom (M, Y)= 0 for all M in C, then c² is a torsion-free class. Conversely, it was shown …

… of a projective R-module P, a necessary and sufficient condition for I to be a TTF-class is that
… In this note we shall give a similar condition for I to be a TTF-class and look at the result due …

… Thus ~ is an epimorphism onto the projective module P and so ~ast split, that is, there is a
monomorphlsm $:P ~ R such that c0o¢ = ip, the identity map of P. In particular, the isomorphic …

… a projective module is idempotent. We show that this is in fact a consequence of the natural
way in which every projective module … TTF class is the torsionfree class of a cotorsion radical, …

… class is a TTF-c\&ss (Corollary 1.6). To further point out the analogy between the class &~
and the usual torsion modules, we … -free simple modules are projective, then & is a TTF-class. …

… (2) If T is stable and IR is finitely geherated, then (R/IlR is finitely presented; since R/I is right
R-flat by Theorem 2, we conclude that R/I is projective as a right R-module (Villamayor, in …

… A projective module P will … , B and P are equivalent categories, and P consists of small
projective objects of (C*,Ab). P generates a torsion class T from which a TTF theory (T,S,R) can be …

… In this paper we classify one-sided split TTF-triples in module … A TTF-class T gives rise to a
triple ( C , T , F ) , which we shall … B -module P is projective over B if, and only if, it is projective …

… TTF triple defined by a finitely generated projective module whose trace in R is finitely generated,
then Ht is a module … , T ⊥), for some TTF class T , will be called a TTF triple and the two …