step  simplex   boundary                 reduction (add earlier reduced columns until low is new)      result
  1   3         {}                                                                                      R=0: positive
  2   4         {}                                                                                      R=0: positive
  3   2         {}                                                                                      R=0: positive
  4   0         {}                                                                                      R=0: positive
  5   1         {}                                                                                      R=0: positive
  6   23        {3,2}                                                                                   low=2: PAIR (2,23)
  7   13        {3,1}                                                                                   low=1: PAIR (1,13)
  8   01        {0,1}                   +R(13)={3,1} -> {3,0}                                           low=0: PAIR (0,01)
  9   02        {2,0}                   +R(01)={3,0} -> {3,2} +R(23)={3,2} -> {}                        R=0: positive
 10   12        {2,1}                   +R(13)={3,1} -> {3,2} +R(23)={3,2} -> {}                        R=0: positive
 11   04        {4,0}                   +R(01)={3,0} -> {3,4}                                           low=4: PAIR (4,04)
 12   24        {4,2}                   +R(23)={3,2} -> {3,4} +R(04)={3,4} -> {}                        R=0: positive
 13   14        {4,1}                   +R(13)={3,1} -> {3,4} +R(04)={3,4} -> {}                        R=0: positive
 14   024       {02,04,24}                                                                              low=24: PAIR (24,024)
 15   012       {01,02,12}                                                                              low=12: PAIR (12,012)
 16   124       {12,24,14}                                                                              low=14: PAIR (14,124)
 17   34        {3,4}                   +R(04)={3,4} -> {}                                              R=0: positive
 18   234       {23,24,34}                                                                              low=34: PAIR (34,234)
 19   134       {13,14,34}              +R(234)={23,24,34} -> {23,13,24,14} +R(124)={12,24,14} -> {23,13,12} +R(012)={01,02,12} -> {23,13,01,02}  low=02: PAIR (02,134)
V_P: [('0', '01'), ('1', '13'), ('12', '012'), ('14', '124'), ('2', '23'), ('24', '024'), ('34', '234'), ('4', '04')]
closed V-path: None
non-incident: [('02', '134')]
pair {02,134}: paths in V_P: 3 ['134 34 234 24 024 02', '134 14 124 24 024 02', '134 14 124 12 012 02']
