A tautology is a compound proposition that is:a.Always trueb.Always falsec.Either true or falsed.Neither true nor false

Understanding Tautology

A tautology in propositional logic is a statement that is true in every possible interpretation. Essentially, it means that no matter what the truth values of the individual components are, the overall statement will always evaluate to true.

Answer to the Question

1. Option A: Always True - This is the correct definition of a tautology.
2. Option B: Always False - This describes a contradiction, not a tautology.
3. Option C: Either True or False - This describes a general statement, which is not specific for tautologies.
4. Option D: Neither True nor False - This does not apply as all propositions must adhere to either true or false in classical logic.

Final Answer

The correct answer is a. Always true. A tautology is indeed a compound proposition that is always true, regardless of the truth values of its constituent propositions.