M. Sekizawa, Tokyo Gakugei University, Koganei-shi Nukuikita-machi 4-1-1, Tokyo 184-8501, JAPAN
E-mail: sekizawa@u-gakugei.ac.jp
Abstract. An explicit classification of the spaces in the title is given. The resulting spaces are locally products or locally warped products of the real line and two-dimensional spaces of \textit{constant} curvature.
AMSclassification. 53C20, 53C21, 53C25
Keywords. Riemannian manifold, conformally flat space, pseudo-symmetric space, warped product