! Articial data
! When X1 + X2 < 10, there is one outcome.
! When X1 + X2 > 10, there is the other outcome.
X1 X2 S N
 2  2 0 1
 2  4 0 1
 2  6 0 1
 2  8 1 1
 4  2 0 1
 4  4 0 1
 4  6 0 1
 4  8 1 1
 6  2 0 1
 6  4 1 1
 6  6 1 1
 6  8 1 1
 8  2 0 1
 8  4 1 1
 8  6 1 1
 8  8 1 1