  In this paper, based on ideals, we investigate residuated lattices from fuzzy
set theory and lattice theory point of view. Ideals are important concepts in
the theory of algebraic structures used for formal fuzzy logic and first, we
investigate the lattice of fuzzy ideals in residuated lattices. Then we present
applications of fuzzy sets in Coding Theory and we study connections between
fuzzy sets associated to ideals and Hadamard codes.
