llvm/polly/lib/External/isl/test_inputs/convex1.polylib

# {j,N | 0<=j<=N-1; 2<=N}
4 4
1   1  0   0
1  -1  1  -1
1   0  1  -2
1   0  0   1
# {j, N | 1<=j<=N; 1<=N}
4 4
1  1  0  -1
1 -1  1   0
1  0  1  -1
1  0  0   1
# {j,N | 0<=j<=N; 2<=j+N}
3 4
   1    1    1   -2
   1    1    0    0
   1   -1    1    0