  PECR is a formal system designed to explore the properties of computability
of programs on a real-world computer. As such PECR incorporates the finite
resources of the machine upon which a program is to be executed. The main
features of the formal system will be presented and its practical applications
will be discussed. Of particular interest is the implementation of the formal
system to the exploration of the laws of nature that lead to rigorous
constructions of computer models of real-world phenomena.
