Our model is based on a formal notion of textual definition.
we assume a definition contains the following fields (Storrer and Wellinghoff 2006): r The DEFINIENDUM field (DF): this part of the definition includes the definiendum (that is, the word being defined) and its modifiers (e.g., "In computer science, a pixel"); r The DEFINITOR field (VF): which includes the verb phrase used to introduce the definition (e.g., "is"); r The DEFINIENS field (GF): which includes the genus phrase (usually including the hypernym, e.g., "a dot"); r The REST field (RF): which includes additional clauses that further specify the differentia of the definiendum with respect to its genus (e.g., "that is part of a computer image").