state transitions cluster__p p cluster__p_region2 region2 cluster__p_region1 region1 __initial _outer outer __initial->_outer _p_region2_s4 s4 enter ^out.s4 _outer->_p_region2_s4 _p_region2_initial _p_region2_s3 s3 enter ^out.s3 _p_region2_initial->_p_region2_s3 _p_region1_initial _p_region1_s1 s1 enter ^out.s1 _p_region1_initial->_p_region1_s1 _p_region1_s2 s2 enter ^out.s2