May 21, 2021
•

# Rules of Inference

*Modus ponens*— P implies Q. P is true. Therefore Q must also be true.*Modus tollens*— P implies Q. Q is not true. Therefore P must not be true.*Modus trollens*— I believe P, therefore P is true.

May 21, 2021
•

*Modus ponens*— P implies Q. P is true. Therefore Q must also be true.*Modus tollens*— P implies Q. Q is not true. Therefore P must not be true.*Modus trollens*— I believe P, therefore P is true.