Practice question · Select all that apply
Which are correct statements of De Morgan’s laws?
Hints
- Three are correct; one fails to flip the connective.
- De Morgan always swaps conjunction for disjunction when the negation moves inward.
Show the answer
- A. not (P and Q) is equivalent to not-P or not-Q
- B. Negating a conjunction produces a disjunction
- C. not (P or Q) is equivalent to not-P and not-Q
Why
The connective flips when negation moves inside. the fourth option keeps the conjunction, which is the standard error: "not both" does not mean "neither".
Practise Truth Tables
The app has 3 more questions on this lesson, and keeps your place in the course. Philosophy I is free to start.
More questions on Truth Tables
- How many rows does a truth table need for a sentence containing 5 distinct atomic propositions?
- Why does the exponential growth of truth tables motivate natural deduction?
- Two sentences count as logically equivalent as soon as their truth-table columns agree in at least one row.
- Arrange the steps of building a truth table in order.
- Propositional logic is termed decidable because truth tables offer an exhaustive decision procedure. What…
- Match each truth-table result to what it establishes about an argument.
- A sentence contains 4 distinct atomic propositions. Set the number of rows its truth table requires.