PNS --- Is a public domain Petri net simulation tool for Unix systems. PNS is a graphics tool and requires the X window system. see also www-page: http://www.informatik.uni-stuttgart.de/ipvr/bv/pns/pns.html Examples: --------- - simple.net 3-2 Reduction - add.net x = x + y - sub1.net x >= y : x = x - y x < y : y = y - x - sub2.net x = x - y NEGATIVE = 1 <=> x-y < 0 - mult.net z = x * y - phil.net Dining Philosophers Problem