Chatuskoti (Catuskoti - Tetralemma - චතුස්තෝටිකය) is a logic system that existed in ancient India and Sri Lanka. It can be called the logic of Buddhism. It is more like an extension to the modern Binary logic. You may download the presentation to view the Sinhala text (if you have Sinhala unicode installed). You may need to install Unicode Sinhala Fonts to view the Sinhala text at http://www.siyabas.lk. (the Sinhala text is displayed correctly in the presentation transcript, which is displayed below)