Gap size: 4bp     combination occurs in      layer 7      |
motif occurs in layer 5~7          |   Gap size: 3bp   combination occurs in    layer 7    |
motif occurs in layer 7          | motif occurs in layer 7          |
F | F | T | T | F | T | T | T | T |
| OR |    Gap size: 7bp    combination occurs in     layer 7     |
motif occurs in layer 7          | motif occurs in layer 7          |
T | T |
|