 Alternatively, one can use a variable-binding operator, \(\lambda\), that, given an open wff, generates a term (called a “lambda abstract”) that is meant to stand for a property. This way to proceed is more flexible and is followed in the most recent versions of property theory. We shall thus stick to it in the following. To illustrate, we can apply “\(\lambda\)” to the open formula, “\((R(x) \amp S(x))\)” to form the one-place complex predicate “[\(\lambda x (R(x) \amp S(x))\)]”; if “\(R\)” denotes being red and “\(S\)” denotes being square, then this complex predicate denotes the compound, conjunctive property being red and square. Similarly, we can apply the operator to the open formula “\(\exists y(L(x, y))\)” to form the one-place predicate “[\(\lambda x \exists y(L(x, y))\)]”; if “\(L\)” stands for loves, this complex predicate denotes the compound property loving someone (whereas “[\(\lambda y \exists x(L(x, y))\)]” would denote being loved by someone). To ensure that lambda abstracts designate the intended property, one should assume a “principle of lambda conversion”. Given option 1, it can be stated thus: