Considering an elementary proposition 'aRb' and its negation '~aRb', it is stated that these two propositions have opposite sense. To say, the state of affairs aRb exists implies if a does bear the relation R to b then 'aRb' is true and '~aRb' is false. In this connection, Wittgenstein states that "names are like points, propositions like arrows and they have sense" (Tractatus, 3.144). This is so because a name like a, or b, is static. It does not move. It refers to certain object whereas proposition moves. The proposition aRb moves from a to b. Thus a proposition is a truth function of elementary proposition.

Wittgenstein in his picture theory of meaning states that all genuine propositions are truth functions of elementary propositions. On this account, Anscombe writes that the picture theory does not permit any functions of propositions other than truth functions. Indeed, we should not regard Wittgenstein's theory of proposition as a synthesis of a picture theory of truth functions; his picture theory and theory of truth functions are one and the same (Anscombe, 1971,81). The essence of the truth functions of a proposition states that the world divides into atomic facts. There are no irreducible general facts. So, all general facts can be reduced to atomic facts. Hence, all propositions state about the atomic facts of the world. As a result, it corresponds to the objects of the world. Therefore, all propositions can have truth-value. If the proposition does not correspond to the facts of the world then the proposition is false. On the contrary, if the proposition corresponds to the facts of the world then the proposition is true.

A complex situation is described by a truth function of elementary propositions. An elementary proposition describes the state of affairs which makeup the complex situation, so the only terms that could denote whatever that is supposed to bind the state of affairs together are the truth functional operators, the so called logical constants (Pitcher, 1972,70). Logically speaking, two elementary propositions are neither contradictory nor contrary to each other. It is so because elementary proposition expresses the state of affairs of the world. Since states of affairs are independent from each other it entails that a particular elementary proposition is neither reduced to another nor is deduced from another. In this connection, Wittgenstein states that "from the existence or non-existence of one state of affairs it is impossible to infer the existence or non-existence of another" (Tractatus, 2.062).