(0) Obligation:

Q restricted rewrite system:
The TRS R consists of the following rules:

h(f(x, y)) → f(y, f(h(h(x)), a))

Q is empty.

(1) Overlay + Local Confluence (EQUIVALENT transformation)

The TRS is overlay and locally confluent. By [NOC] we can switch to innermost.

(2) Obligation:

Q restricted rewrite system:
The TRS R consists of the following rules:

h(f(x, y)) → f(y, f(h(h(x)), a))

The set Q consists of the following terms:

h(f(x0, x1))

(3) DependencyPairsProof (EQUIVALENT transformation)

Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem.

(4) Obligation:

Q DP problem:
The TRS P consists of the following rules:

H(f(x, y)) → H(h(x))
H(f(x, y)) → H(x)

The TRS R consists of the following rules:

h(f(x, y)) → f(y, f(h(h(x)), a))

The set Q consists of the following terms:

h(f(x0, x1))

We have to consider all minimal (P,Q,R)-chains.
 java.lang.AssertionError: Constraint not solved at aprove.DPFramework.DPProblem.Processors.QDPReductionPairProcessor.getResult(QDPReductionPairProcessor.java:414) at aprove.DPFramework.DPProblem.Processors.QDPReductionPairProcessor.getResult(QDPReductionPairProcessor.java:194) at aprove.DPFramework.DPProblem.Processors.QDPReductionPairProcessor.processQDPProblem(QDPReductionPairProcessor.java:166) at aprove.DPFramework.DPProblem.Processors.QDPProblemProcessor.process(QDPProblemProcessor.java:51) at aprove.Strategies.ExecutableStrategies.Executor.execute(Executor.java:153) at aprove.Strategies.ExecutableStrategies.Executor$Runner.wrappedRun(Executor.java:176) at aprove.Strategies.Util.FancyRunner.run(FancyRunner.java:82) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:636)