MAYBE
af/ONE-SORTED/705.trs
Input rules:
   [ a -> c,
     c -> a,
     c -> h(a,c) ]
Sorts having no ground terms: 
Rules applicable to ground terms:
   [ a -> c,
     c -> a,
     c -> h(a,c) ]
Constructor pattern: [h(?x_1,?x_2)]
Defined pattern: [c,a]
Constructor subsystem:
   [ ]
Modified Constructor subsystem:
   [ ]
candidate for c:
   [ c -> a ]
candidate for a:
   [ a -> c ]
Find a quasi-ordering ...
encodeSameNthStatus h/0, h/1
encodeSameNthStatus(sub) logArF:1, logArG:1
failed to find an ordering.
Try to supplement auxiliary rules.
{}{}{c}Supplemented Rules:
   [ ]
failed to supplement auxiliary rules
check Non-Ground-Confluence...
ground constructor terms for instantiation: {}
ground terms for instantiation: {a:o}
obtain 10 rules by 3 steps unfolding
obtain 100 candidates for checking non-joinability
check by TCAP-Approximation (failure)
check by Ordering(rpo), check by Tree-Automata Approximation (failure)
check by Interpretation(mod2) (failure)
check by Descendants-Approximation, check by Ordering(poly) (failure)
: Failure(unknown)
(727 msec.)
2.79