KwickClips Computer Systems · 37 sec · free
Is p ∧ ~p a tautology?
Short answer. No, it is a contradiction.
How do you decide the type?
Read the last column.
Three types
| Type | Column | Example |
|---|---|---|
| Tautology | all T | p ∨ ~p |
| Contradiction | all F | p ∧ ~p |
| Contingency | mixed | p → q |
Remember
| Look at the last column |
Can a statement be true in every single row? Yes. A tautology is always true. A contradiction is always false. A contingency is sometimes true. One tip. Just read the last column.
This clip is from the full lesson: Propositional Logic: Propositions, Connectives and Valid Formulae — 8 minutes, with the tables, the quick answers and the whole lesson in text.
Useful for: ISC Class 11 Computer Science (868), ISC Class 12 Computer Science (868), ISC Class 12 Computer Science (868)
More KwickClips from this lesson
Is a question a proposition?40 sec
How many rows make p → q false?42 sec
Is every valid formula satisfiable?42 secVoice-over is AI-generated; the script is written and checked by Kajal Ma'am. Confirm anything you plan around against your official board document. We never ask for a password or an OTP.