x1 x2 x3 x4 y
-1 -1 -1 -1 7.37
1 -1 -1 1 7.66
-1 1 -1 1 7.67
1 1 -1 -1 7.79
-1 -1 1 1 7.52
1 -1 1 -1 7.64
-1 1 1 -1 7.54
1 1 1 1 7.90