YES
af/ONE-SORTED/761.trs
Input rules:
   [ a -> b,
     a -> d,
     b -> a,
     c -> a,
     c -> b ]
Sorts having no ground terms: 
Rules applicable to ground terms:
   [ a -> b,
     a -> d,
     b -> a,
     c -> a,
     c -> b ]
Constructor pattern: [d]
Defined pattern: [c,b,a]
Constructor subsystem:
   [ ]
Modified Constructor subsystem:
   [ ]
candidate for c:
   [ c -> a ]
   [ c -> b ]
candidate for b:
   [ b -> a ]
candidate for a:
   [ a -> b ]
   [ a -> d ]
Find a quasi-ordering ...
order successfully found
Precedence:
 b : Mul;
 c : Mul;
 a : Mul;
 d : Mul;
Rules:
   [ c -> a,
     b -> a,
     a -> d ]
Conjectures:
   [ a = b,
     c = b ]
STEP 0
ES:
   [ a = b,
     c = b ]
HS:
   [ ]
ES0:
   [ d = d,
     d = d ]
HS0:
   [ ]
ES1:
   [ ]
HS1:
   [ ]
: Success(GCR)
(2 msec.)
0.02