I dont know if anyone here has studied software testing, but if so, I need an explanation of exactly what All-defs / All-uses are. I know they are differnt ways to define paths to conduct data flow anaysis through a block of code, but I am having difficulty understanding how they differ. I probably just need an alternate explanation for them, as the information i have in my course notes isnt making sence. All I seem to be understanding from this is that in all-defs criteria we need a path from a variable definition to ONE useage of that variable, but for all uses you need a path from a definition to ALL uses of that variable...and every other node in a control flow graph thereafter... I dont really know if that interpretation is correct... Any help would be appreciated.