This paper presents a formal 'fragment' of database semantics as a declarative model of a cognitive agent. It is called a SLIM machine and functionally integrates the procedures of natural language interpretation, conceptualization, and production as well as query and inference. Each of these functions is illustrated explicitly by a corresponding LA-grammar. In addition, a control structure based on the principle of balance is presented. This principle mediates between the knowledge of the SLIM machine and its current situation by selecting a suitable action.