One concept that I found useful in Truth Tables was a tautology. A compound claim is a tautology if it is true for every possible assignment of truth-values to its parts. In a tautology it doesn't matter whether A is true or false. Any claim with the form A v L A is true. (v representing or and L representing not)
For example, I am a girl or I am not a girl
A v L A
A L A A V L A
T F T
F T T
Compound Claims
In Chapter 6, Epstein explains that a compound claim is a claim that is composed of other claims, but is to be viewed as just one claim using and, or, not, if, then.
The negation of a claim is one that has opposite truth value in all possible circumstances.
I work in a consignment boutique this summer and I realized I use compound claims everyday. For example a customer brings in items to be sold in the store. I let the customer know the it is 30 day consignment with 65% for them and 35% for the owner. If their item sells in 30 days they can come pick up their check or they can receive store credit. The negation of this would be If their item does not sell in 30 days they will not receive a check or store credit and they can come pick up their item or donate the item to charity.
