Key points are not available for this paper at this time.
In this note, a necessary and sufficient condition for a trivial extension to be a left p.p.-ring is obtained. As an application, we determine when a trivial Morita context is a left p.p.-ring, and a result of Xue On p.p. rings, Kobe J. Math. 7 (1990) 77–80 characterizing triangular p.p.-rings follows immediately.
M. Tamer Koşan (Sun,) studied this question.