National audienceProduction Rules or Business Rules are of the form 'if (condition) then (action)'. Sets of such rules can be executed on input data according to execution algorithms, or analyzed semantically using operational semantics, but the universality of systems or sets of such rules has never been characterized formally, to the best of our knowledge. Our goal is to show that for a simple execution algorithm, sets of Business Rule form a universal programming language. In other words, we show that Business Rules are Turing-complete. The proof consists in showing that a Business Rule program can be transformed in a WHILE program using additional variables. The implications of such a WHILE form include a type of structural operational ...