Each formula of LPCR specifies an algorithm for its evaluation, that is, for the determination of its truth value (if possible). Moschovakis identifies the sense of a formula with that algorithm. Two formulas that evaluate to the same result, thus having the same denotation, may have different senses because the associated algorithms are different. For example, in \eqref{evenone} we gave a formula that defines the even numbers. Here is another such formula. 