Logical Connectives

What you will be able to do

• Translate each connective into a P → Q conditional with the antecedent and consequent identified.
• Write the contrapositive and use it as an equivalent of the original.
• Apply modus ponens and modus tollens as the only two valid one-step inferences.
• Reject affirming-the-consequent and denying-the-antecedent conclusions.

What is inside this lesson

1. 1Everything reduces to 'if P then Q'
2. 2Translating the connectives
3. 3The contrapositive and the two valid moves
4. 4Worked examples
5. 5Common mistakes
6. 6Quick revision
7. 7Practice