or functional calculus, n. the system of symbolic logic concerned not only to represent the logical relations between sentences or propositions as wholes, but also to consider their internal structure in terms of subject and predicate. The primitive terms are individual names, predicates, and variables that may be bound by quantifiers. If quantification is restricted to individuals, it is lower (or first order) predicate calculus (LPC), and is consistent, complete, but not decidable. See also logical form. Compare sentential calculus.