YES
(ignored inputs)COMMENT Cops #647 - #721: generated ground TRSs; evenly distributed in the UNR/UNC/NFP/CR hierarchy submitted by: Bertram Felgenhauer
Input:
   [ b -> b,
     a -> h(f(c),h(a,f(c))),
     f(f(h(a,h(b,b)))) -> a,
     h(c,c) -> b,
     b -> h(f(b),b) ]

Make it flat:
   [ f(!cl_2) -> a,
     !cl_2 -> !cl_2,
     f(!cl_1) -> !cl_2,
     a -> h(!cr_0,!cr_2),
     !cr_2 -> h(a,!cr_1),
     !cr_1 -> f(c),
     !cr_0 -> f(c),
     b -> b,
     !cl_0 -> !cl_0,
     h(b,b) -> !cl_0,
     b -> h(!cr_3,b),
     !cr_3 -> f(b),
     h(c,c) -> b,
     h(a,!cl_0) -> !cl_1,
     !cl_1 -> !cl_1 ]
Time: 0.000 [s]

Make it Complete (R^):
   [ f(!cl_2) = h(!cr_0,!cr_2),
     f(!cl_2) = h(!cr_1,!cr_2),
     f(!cl_2) = a,
     f(!cl_1) = !cl_2,
     h(!cr_1,!cr_2) = h(!cr_0,!cr_2),
     h(!cr_1,!cr_2) = a,
     a = h(!cr_0,!cr_2),
     h(a,!cr_0) = h(a,!cr_1),
     h(a,!cr_0) = !cr_2,
     !cr_2 = h(a,!cr_1),
     !cr_1 = !cr_0,
     !cr_1 = f(c),
     !cr_0 = f(c),
     h(b,b) = !cl_0,
     h(!cr_3,b) = h(c,c),
     b = h(!cr_3,b),
     !cr_3 = f(b),
     h(c,c) = b,
     h(a,!cl_0) = !cl_1 ]
Time: 0.002 [s]

CPNF:
   [ !cr_0 … f(c),
     c … c ]
Time: 0.000 [s]

Now checking all the pairs in CW...

Time to check pairs: 0.000 [s]

The TRS has Uniqueness of Normal Forms.
Total Time: 0.003 [s]

problems/666.trs: Success(UNC)
real 0.02
user 0.01
sys 0.01