First notions of logic (preparatory to the study of geometry)

Augustus De Morgan

Augustus De Morgan was a British mathematician and logician. He is best known for De Morgan's laws relating logical conjunction, disjunction, and negation, and for coining the term "mathematical induction", the underlying principles of which he formalized. De Morgan's contributions to logic are heavily used in many branches of mathematics, including set theory and probability theory, as well as other related fields such as computer science.