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)
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Is a question a proposition?40 sec
How many rows make p → q false?42 sec
Is every valid formula satisfiable?42 secDisclaimer. KwickAcademy is free study material for general learning and revision. Parts of it, including the voice-over, are produced with the help of AI tools and may contain errors; if you spot one, please tell us and we will correct it. Syllabus, marks and exam details follow the latest official board publications available to us, and boards can change them at any time, so always confirm against your board's official website and your school. Using this material does not guarantee any marks or result. Board names and trademarks belong to their owners; Kwickprep is not affiliated with or endorsed by any examination board. We never ask for passwords, OTPs or ID numbers. Your progress is saved only in this browser. Full disclaimer · Privacy