Editing Hoare logic (section)

==Hoare triple==
The central feature of '''Hoare logic''' is the '''Hoare triple'''. A triple describes how the execution of a piece of code changes the state of the computation. A Hoare triple is of the form

: <math>\{P\} C \{Q\}</math>

where <math>P</math> and <math>Q</math> are ''[[assertion (computing)|assertions]]'' and <math>C</math> is a ''command''.<ref group=note>Hoare originally wrote "<math>P\{C\}Q</math>" rather than "<math>\{P\}C\{Q\}</math>".</ref> <math>P</math> is named the ''[[precondition]]'' and <math>Q</math> the ''[[postcondition]]'': when the precondition is met, executing the command establishes the postcondition. Assertions are formulae in [[predicate logic]].

Hoare logic provides [[axiom]]s and [[inference rule]]s for all the constructs of a simple [[Imperative programming|imperative programming language]]. In addition to the rules for the simple language in Hoare's original paper, rules for other language constructs have been developed since then by Hoare and many other researchers. There are rules for [[Concurrency (computer science)|concurrency]], [[procedure (computer science)|procedure]]s, [[jump (computer science)|jump]]s, and [[pointer (computer programming)|pointer]]s.