+-----(b)->[S1]-+ | | +-----(a)->[test b]-+ +---->[S5]-+ | | | | | +-(not-b)->[S2]---+ | [test a]-+ | | +->[end] | | | | | +-----(c)->[S3]-+ | | | | +-->[S6]-+ +-(not-a)->[test c]-+ | | | +-(not-c)->[S4]---+