kontrapositsioon

Kontrapositsioon is a concept in logic and philosophy related to conditional statements. A conditional statement, often expressed as "If P, then Q," where P is the antecedent and Q is the consequent, has a contrapositive form. The contrapositive of "If P, then Q" is "If not Q, then not P."

The key characteristic of the contrapositive is that it is logically equivalent to the original conditional statement. This means that if the original statement is true, its contrapositive is also true, and if the original statement is false, its contrapositive is also false. This logical equivalence makes the contrapositive a useful tool in proofs and logical reasoning.

For example, consider the statement "If it is raining, then the ground is wet." The contrapositive of this statement is "If the ground is not wet, then it is not raining." These two statements convey the same logical relationship. If the first is true, the second must also be true, and vice versa.

The contrapositive should not be confused with the inverse ("If not P, then not Q") or the converse ("If Q, then P"), which are not logically equivalent to the original conditional statement. Understanding the contrapositive is fundamental for manipulating and analyzing logical propositions accurately.