Lexical-Functional Grammar (LFG) starts from the idea that grammatical knowledge is factored into different levels of representation, which encode different kinds of information, and are in not in a one-one mapping relation. LFG makes a sharp distinction between some grammatical information (at f-structure) and the overt structure which expresses that information (the c-structure). The c-structure encodes phrasal dominance and precedence relations, represented as a phrase structure tree. In contrast, the f-structure encodes information about the functional relations between the parts, such as what is the subject and what is the predicate, what agreement features are present, and so on. F-structure presents all of the grammatically relevant information about a sentence or other unit of analysis. C-structure is a representation of constituency, categorial labeling, and linear precedence relations. One central idea of the LFG approach is that the truly universal aspects of syntax are determined with regard to f-structure information.