A test tool is provided for testing a software component. The quantative variable is referred to as the Interest Priority Value. Further, the exhaust purification apparatus includes a urea injection unit for feeding of a reducing agent upstream of the urea selective reduction catalyst in the exhaust passageway and an ammonia sensor for detection of the ammonia concentration at a site between the first selective reduction catalyst and the second selective reduction catalyst in the exhaust passageway. The cleaning member includes a resilient sheet member capable of providing resilient contact with a segment of the support surface in the cleaning position during rotation of the rotatable member. The range may cover a range of various material compositions andor cure characteristics. The hydraulic system includes a pressure regulator that maintains the output pressure from a hydraulic pump above a predetermined minimum pressure.