ABSTRACT
One-place predicates such as ‘x is happy’, ‘x is green’, ‘x is square’ express properties which can be possessed by single objects. Two-place predicates such as ‘x loves y’, ‘x is the brother of y’, ‘x is taller than y’ express two-term relations which can be possessed by pairs of objects. Three-place predicates such as ‘x is between y and z’ express three-term relations which can hold between triples of objects. In this chapter we study the properties of two-term relations, a subject of great philosophical and mathematical interest.
