For a residuated lattice A we denote by Ds(A) the lattice of all deductive systems (congruence filters) of A. The aim of this paper is to put in evidence new characterizations for maximal and prime elements of Ds(A) and to characterize archimedean and hyperarchimedean residuated lattices; so we prove some theorems of Nachbin type for residuated lattices. These results generalize to the case of residuated lattices some results earlier obtained by Buşneag and Piciu for the case of BL-algebras.Mathematics Subject Classification 2000: 03G10, 06B20.

In this paper we introduce the notions of MT L algebra of fractions and maximal MT L algebra of quotients for a MT L algebra and prove constructively the existence of a maximal MT L algebra of quotients (see Buşneag & Piciu, 2005, for BL algebras).