Logic is the science of reasoning and the study of argument forms. This page is all about symbolic logic. That is, we can take statements in words, and represent them sybolically. We use letters to represent statements. A Truth Table is a handy way to represent the possible truth values of statements.
Every statement has a negation .
The truth value of the negation of a true statement is false. Here's the truth table. Here's the truth table. If it is Friday then it is raining. If it is raining then it is Friday.