摘要: Our first goal is to characterize the consequence relation in a first-order language by means of calculus similar that propositional logic. That this attainable at all was shown for time Gdel [Go1]. The original version Gdel’s theorem refers axiomatization tautologies only and does not immediately imply compactness logic; but more general formulation completeness 3.2 does. importance mathematical applications revealed 1936 A. Malcev, see [Ma].