YES

   1: a1() -> b1()
   2: a1() -> c1()
   3: b1() -> b2()
   4: c1() -> c2()
   5: a2() -> b2()
   6: a2() -> c2()
   7: b2() -> b3()
   8: c2() -> c3()
   9: a3() -> b3()
  10: a3() -> c3()
  11: b3() -> b4()
  12: c3() -> c4()
  13: a4() -> b4()
  14: a4() -> c4()
  15: b4() -> b5()
  16: c4() -> c5()
  17: a5() -> b5()
  18: a5() -> c5()
  19: b5() -> b6()
  20: c5() -> c6()
  21: a6() -> b6()
  22: a6() -> c6()
  23: b6() -> b7()
  24: c6() -> b7()
  25: b7() -> b1()
  26: b7() -> c1()

@Rule Labeling
--- R
   1: a1() -> b1()
   2: a1() -> c1()
   3: b1() -> b2()
   4: c1() -> c2()
   5: a2() -> b2()
   6: a2() -> c2()
   7: b2() -> b3()
   8: c2() -> c3()
   9: a3() -> b3()
  10: a3() -> c3()
  11: b3() -> b4()
  12: c3() -> c4()
  13: a4() -> b4()
  14: a4() -> c4()
  15: b4() -> b5()
  16: c4() -> c5()
  17: a5() -> b5()
  18: a5() -> c5()
  19: b5() -> b6()
  20: c5() -> c6()
  21: a6() -> b6()
  22: a6() -> c6()
  23: b6() -> b7()
  24: c6() -> b7()
  25: b7() -> b1()
  26: b7() -> c1()

--- S
   1: a1() -> b1()
   2: a1() -> c1()
   3: b1() -> b2()
   4: c1() -> c2()
   5: a2() -> b2()
   6: a2() -> c2()
   7: b2() -> b3()
   8: c2() -> c3()
   9: a3() -> b3()
  10: a3() -> c3()
  11: b3() -> b4()
  12: c3() -> c4()
  13: a4() -> b4()
  14: a4() -> c4()
  15: b4() -> b5()
  16: c4() -> c5()
  17: a5() -> b5()
  18: a5() -> c5()
  19: b5() -> b6()
  20: c5() -> c6()
  21: a6() -> b6()
  22: a6() -> c6()
  23: b6() -> b7()
  24: c6() -> b7()
  25: b7() -> b1()
  26: b7() -> c1()