Rule of Inference (Paperback)

High Quality Content by WIKIPEDIA articles! In logic, a transformation rule or rule of inference is a syntactic rule or function which takes premises and returns a conclusion (or in multiple-conclusion logic, conclusions). For example, the rule of inference modus ponens takes two premises, one of the form "If p then q" and another of the form p and returns the conclusion q. The rule is sound with respect to the semantics of classical logic (as well as the semantics of many other non-classical logics), in the sense that if the premises are true (under an interpretation) then so is the conclusion.