4
[1: -1.0 0.0 1.0 0.0]
[1:  0.0 0.0 0.0 1.0]
3
[1:[1: 1 4] [1: 2 4] [1: 3 4]]
6
[1:[1: 1 1] 
          [1: 1 2]
          [1: 2 1]
          [1: 2 2]
          [1: 3 1]
          [1: 3 2] ]
1
[1: [1: 4 2] ]
[1: -2.0 ]
