TRS:
 {   a__g(X) -> a__h(X),
      a__c() -> d(),
   a__h(d()) -> a__g(c()),
  mark(g(X)) -> a__g(X),
  mark(h(X)) -> a__h(X),
   mark(c()) -> a__c(),
   mark(d()) -> d(),
     a__g(X) -> g(X),
     a__h(X) -> h(X),
      a__c() -> c()}
 Fail