 The society relies greatly on infrastructure such as water, energy, communication and transportation, which again all rely on fully functionally working computer systems.There are several well known examples of when critical systems fail due to bugs or errors in software, such as "when shortage of computer memory caused LAX computers to crash and hundreds of flights to be delayed" (April 30, 2014).Traditionally, the mechanisms used to control the correct behavior of software are implemented at the operating system level.