section_path: Applications/Logic
section_name: Logic
paragraph_text: Logic
  
  Logic is the study of correct reasoning. Algebraic logic employs algebraic methods to describe and analyze the structures and patterns that underlie logical reasoning. One part of it is interested in understanding the mathematical structures themselves without regard for the concrete consequences they have on the activity of drawing inferences. Another part investigates how the problems of logic can be expressed in the language of algebra and how the insights obtained through algebraic analysis affect logic.
  
  Boolean algebra is an influential device in algebraic logic to describe propositional logic. Propositions are statements that can be true or false. Propositional logic uses logical connectives to combine two propositions to form a complex proposition. For example, the connective "if... then" can be used to combine the propositions "it rains" and "the streets are wet" to form the complex proposition "if it rains then the streets are wet". Propositional logic is interested in how the truth value of a complex proposition depends on the truth values of its constituents. With Boolean algebra, this problem can be addressed by interpreting truth values as numbers: 0 corresponds to false and 1 corresponds to true. Logical connectives are understood as binary operations that take two numbers as input and return the output that corresponds to the truth value of the complex proposition. Algebraic logic is also interested in how more complex systems of logic can be described through algebraic structures and which varieties and quasivarities these algebraic structures belong to.