Logic is the use and study of valid . The study of logic features most prominently in the subjects of philosophy, , and computer science. Logic was studied in several ancient , including India, China, Persia and Greece. In the West, logic was established as a formal by Aristotle, who gave it a fundamental place in philosophy. The study of logic was part of the classical trivium (三学科), which also included and rhetoric. Logic was further by Al-Farabi who categorized it into two separate groups (idea and ). Later, Avicenna revived the study of logic and developed relationship between temporalis and the (时间与意义). In the East, logic was developed by Hindus, Buddhists and Jains (耆那教徒). Logic is often divided into three parts: reasoning, abductive reasoning, and deductive reasoning.