statements that you're allowed to assume. The conclusion is the statement that you need to prove. The idea is to operate on the premises using rules of inference until you arrive at the conclusion.
Rule of Premises. You may write down a premise at any point in a proof.
The second rule of inference is one that you'll use in most logic proofs. It is sometimes called modus ponendo ponens, but I'll use a shorter name.
Modus Ponens. If you know P and $P ifthen Q$ , you may write down Q.
In the rules of inference, it's understood that symbols like "P" and "Q" may be replaced by any statements, including compound statements.