In logic programming, the management of imperfect information has attracted the attention of many researchers and numerous frameworks have been proposed. Addressing all of them is almost impossible, due to both the large number of works published in this field (early works date back to early 80’s [376], see also [416]) and the different approaches proposed. Like for the DL case, essentially they differ in the underlying notion of uncertainty theory and vagueness theory (probability theory, possibilistic logic, fuzzy logic and multi-valued logic) and how uncertainty/vagueness values, associated to rules and facts, are managed.