View source for Propositional calculus

A general name for a deductive system whose deducible objects can be interpreted as statements formed from simple (i.e. not analyzable in the framework of propositional calculus) statements using propositional connectives (such as  "not" ,  "and" ,  "or" ,  "if …, then …" , etc.; see [[Logical calculus|Logical calculus]]). The most important example is the classical propositional calculus, in which statements may assume two values —  "true"  or  "false"  — and the deducible objects are precisely all identically true statements. The interest in propositional calculi is due to the fact that they form the base of almost all logical-mathematical theories, and usually combine relative simplicity with a rich content. In particular, many theoretical and applied problems can be reduced to some problem in the classical propositional calculus.

For references see [[Logical calculus|Logical calculus]].