First-order Logic
First-order logic is a branch of Mathematical Logic that deals with reasoning using Quantifiers and Predicates to express properties and relationships among objects. It is a fundamental system for formalizing and evaluating arguments, and is widely used in Computer Science, Philosophy, and Mathematics. First-order logic is characterized by its use of Variables, Constants, and Functions to represent objects and relations, and its ability to express Quantification over these objects. The system was developed by Gottlob Frege and Bertrand Russell, and has since been extensively studied and applied in various fields, including Artificial Intelligence and Formal Verification. First-order logic is often used in conjunction with other logical systems, such as Higher-order Logic and Modal Logic.