Peirce extends the algebra of terms to deal with particular features of relations. Like other terms, we can have conjunctive, disjunctive, and negative terms. Where f and g are relatives, then fg represents the class of pairs (I,J) such that I bears both f and g to J. Similarly, the disjunctive relative, f+g is such that it represent (I,J) if I bears either f or g to J and f′—the negation of the term f—represents the class of pairs (I,J) such that f does not hold between them. Peirce also has a composition operator, ; , such that f;g names (I,J) if there is some entity K such that f names (I,K) and g names (K,J).