There are many formal systems of logic, and Sentential Logic (SL) is one of the simplest. It is also known as "Propositional Logic". Here you will find tutorials and programs relating to Sentential Logic.
Do not believe in anything simply because you have heard it. Do not believe in anything simply because it is spoken and rumored by many. Do not believe in anything simply because it is found written in your religious books. Do not believe in anything merely on the authority of your teachers and elders.

Buddha