Tautology Contradiction and Contingency

In this class, We discuss Tautology Contradiction and Contingency.

The reader should have prior knowledge of constructing truth tables examples. Click Here.

Universally valid formula or Tautology:

A compound proposition that is always true irrespective of the truth values of the proposition that occur in it is Tautology.

Example:

The below diagram shows the tautology example and truth table.

Contradiction:

A compound proposition that is always false irrespective of the truth values of the proposition that occurs in it is a contradiction.

The below diagram shows the example.

Contingency:

A compound proposition that is neither true nor false is called contingency.

The proposition should have at least one true and false in contingency.