6 D x (y1. x (y2. x (y3. y1 y2 y3)))
\r
7 C x (y1. x (y2. x (y3. y1 y1 y3)))
\r
8 C x (y1. x (y2. x (y3. y1 y3 y3)))
\r
9 C x (y1. x (y2. x (y3. y1 y2 y1)))
\r
10 C x (y1. x (y2. x (y3. y1 y2 y2)))
\r
13 D x (y1. x (y2. x (y3. x (y4. y1 y2 y3 y4))))
\r
14 C x (y1. x (y2. x (y3. x (y4. y1 y2 y3 y1))))
\r
15 C x (y1. x (y2. x (y3. x (y4. y1 y2 y1 y4))))
\r