$!\r
D x (y. x (z. y z))\r
C x (y. x (z. y y))\r
+\r
+$!\r
+D x (y1. x (y2. x (y3. y1 y2 y3)))\r
+C x (y1. x (y2. x (y3. y1 y1 y3)))\r
+C x (y1. x (y2. x (y3. y1 y3 y3)))\r
+C x (y1. x (y2. x (y3. y1 y2 y1)))\r
+C x (y1. x (y2. x (y3. y1 y2 y2)))\r
+\r
+$!\r
+D x (y1. x (y2. x (y3. x (y4. y1 y2 y3 y4))))\r
+C x (y1. x (y2. x (y3. x (y4. y1 y2 y3 y1))))\r
+C x (y1. x (y2. x (y3. x (y4. y1 y2 y1 y4))))\r