Any proposition P can be converted into its negation with a negation operator, producing the new, complex, proposition:
If you have Java, try it out for yourself:
Set the truth values for the propositions P and Q by clicking on the appropriate button beside "P" and "Q" respectively. What is the truth value of Not P? Find out by clicking on the "Compute" button.
Notice that it does not matter whether Q is true or false. Every time, Not P is true if P is false, and false if P is true.
17 August 1996