Then using this theorem he showed the consistency of first order predicate calculus in the form of natural deduction system.
Using this method, the program is represented by a theorem and is proved with first-order predicate calculus.
British Dictionary definitions for predicate calculus
predicate calculus
noun
1.
the system of symbolic logic concerned not only with relations between propositions as wholes but also with the representation by symbols of individuals and predicates in propositions and with quantification over individuals Also called functional calculus See also propositional calculus