YES
(ignored inputs)COMMENT COMMENT cops number: 1091 submitted by: Kiraku Shintani
Rewrite Rules (1):
   [ c -> f(c),
     c -> c,
     f(a) -> b,
     a -> c ]
Rewrite Rules (2):
   [ f(a) -> c,
     b -> c,
     b -> a ]
both left-linear
check commutation with R1 := (1), R2 := (2)
check CPs are development closed...
...failed
check commutation with R1 := (2), R2 := (1)
check CPs are development closed...
...succeeded

result: COM
cops-DWfUED7X.trs: Success(COM)
(0 msec.)