(VAR)
(RULES
  a1 -> b1
  a1 -> c1
  b1 -> b2
  c1 -> c2
  a2 -> b2
  a2 -> c2
  b2 -> b3
  c2 -> c3
  a3 -> b3
  a3 -> c3
  b3 -> b4
  c3 -> c4
  a4 -> b4
  a4 -> c4
  b4 -> b5
  c4 -> c5
  a5 -> b5
  a5 -> c5
  b5 -> b6
  c5 -> c6
  a6 -> b6
  a6 -> c6
  b6 -> b7
  c6 -> c7
  a7 -> b7
  a7 -> c7
  b7 -> b8
  c7 -> c8
  a8 -> b8
  a8 -> c8
  b8 -> b9
  c8 -> c9
  a9 -> b9
  a9 -> c9
  b9 -> b10
  c9 -> c10
  a10 -> b11
  b10 -> b11
  c10 -> b11
)
(COMMENT
Example 13 {R_10} from [HM11]:
doi: http://dx.doi.org/10.1007/s10817-011-9238-x
)