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The given Problem was:
c c -> b b 
a b -> a c b 
b a -> b b 
b c -> c a a 
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A self-embedding rewrite structure for the given SRS is:
   abb (a)^k cb --> abb (a)^2k+4 cb  (#102984)
   pattern overlapped by closure at l-2
      RP: b (a)^k cb --> c (a)^2k+2 cb  (#6446)
          pattern overlapped by pattern
             RP: b (a)^k --> (b)^k+1  (#1)
                 self-overlapping Closure at 1
                    OC: b a --(1)-> b b (#3)
                        Rule
             RP: (b)^k+1 cb --> c (a)^2k+2 cb  (#294)
                 pattern overlapped by closure at r0
                    RP: (b)^k+1 c --> c (a)^2k+1 a  (#16)
                        expand ->
                           RP: (b)^k+1 c --> c (a)^2k+2  (#9)
                               increment
                                  RP: (b)^k c --> c (a)^2k  (#2)
                                      self-overlapping Closure at -1
                                         OC: b c --(1)-> c a a (#4)
                                             Rule
                    OC: a b --(1)-> a c b (#2)
                        Rule
      OC: a b c --(3)-> a b b a a (#31)
          OC+OC at 1
             OC: a b c --(2)-> a c c a a (#11)
                 OC+OC at 2
                    OC: a b --(1)-> a c b (#2)
                        Rule
                    OC: b c --(1)-> c a a (#4)
                        Rule
             OC: c c --(1)-> b b (#1)
                 Rule
Hence, the SRS is non-terminating.