NO af/ONE-SORTED/711.trs Input rules: [ f(h(f(b),a)) -> b, f(c) -> b, b -> f(b) ] Sorts having no ground terms: Rules applicable to ground terms: [ f(h(f(b),a)) -> b, f(c) -> b, b -> f(b) ] Constructor pattern: [f(?x_1),h(?x_1,?x_2),a,c] Defined pattern: [b] Constructor subsystem: [ ] Modified Constructor subsystem: [ ] No orientable rules for b. Add rules, and retry... failed to construct defining rules Retry with a different D/C-partition. Constructor pattern: [f(?x_1),h(?x_1,?x_2),a,c,b] Defined pattern: [] Constructor subsystem: [ f(h(f(b),a)) -> b, f(c) -> b, b -> f(b) ] Modified Constructor subsystem: [ f(h(f(b),a)) -> b, f(c) -> b, b -> f(b) ] Find a quasi-ordering ... order successfully found Precedence: c : Mul, b : Mul; f : Mul; h : Mul; a : Mul; Rules: [ f(h(f(b),a)) -> b, f(c) -> b ] Check confluence of constructor subsystem... Check Termination... Terminating, WCR: CR Conjectures: [ b = f(b) ] STEP 0 ES: [ b = f(b) ] HS: [ ] ES0: [ b = f(b) ] HS0: [ ] ES1: [ b = f(b) ] HS1: [ ] No equation to expand check Non-Ground-Confluence... ground constructor terms for instantiation: {a,c,f(a),f(c),h(a,a),h(a,c),h(c,a),h(c,c)} ground terms for instantiation: {a:o,c:o,f(a):o,f(c):o,h(a,a):o,h(a,c):o,h(c,a):o,h(c,c):o} obtain 11 rules by 3 steps unfolding obtain 66 candidates for checking non-joinability check by TCAP-Approximation (failure) check by Ordering(rpo), check by Tree-Automata Approximation (success) where F = {(a,0),(b,0),(c,0),(f,1),(h,2)} Q = {q_0,q_1,q_{h(f(f(b)),a)},q_{a},q_{b},q_{f(b)},q_{f(f(b))}} Qf = {q_0,q_1} Delta = [ a -> q_{a}, b -> q_1, b -> q_{b}, f(q_1) -> q_1, f(q_1) -> q_{b}, f(q_{h(f(f(b)),a)}) -> q_0, f(q_{b}) -> q_{f(b)}, f(q_{f(b)}) -> q_{f(f(b))}, h(q_{f(f(b))},q_{a}) -> q_{h(f(f(b)),a)} ] Witness for Non-Confluence: : Success(not GCR) (151 msec.) 0.21