

A proposition is the expression of agreement and disagreement with the truthpossibilities of the elementary propositions. 4.41 (1) The truthpossibilities of the elementary propositions are the conditions of the truth and falsehood of the propositions. 4.42 With regard to the agreement and disagreement of a proposition with the truthpossibilities of n elementary propositions there are possibilities. 4.43 (1) Agreement with the truthpossibilities can be expressed by coordinating with them in the scheme the mark "T" (true). Absence of this mark means disagreement. 4.44 (2) The sign which arises from the coordination of that mark "T" with the truthpossibilities is a propositional sign. 4.45 For n elementary propositions there are Ln possible groups of truthconditions. The groups of truthconditions which belong to the truthpossibilities of a number of elementary propositions can be ordered in a series. 4.46 (6) Among the possible groups of truthconditions there are two extreme cases. In the one case the proposition is true for all the truthpossibilities of the elementary propositions. We say that the truthconditions are tautological. In the second case the proposition is false for all the truthpossibilities. The truthconditions are selfcontradictory. In the first case we call the proposition a tautology, in the second case a contradiction. 