Term Rewriting System R:
[x]
f(a, f(f(a, a), x)) -> f(f(a, a), f(a, f(a, x)))

Termination of R to be shown.



   R
Dependency Pair Analysis



R contains the following Dependency Pairs:

F(a, f(f(a, a), x)) -> F(f(a, a), f(a, f(a, x)))
F(a, f(f(a, a), x)) -> F(a, f(a, x))
F(a, f(f(a, a), x)) -> F(a, x)

Furthermore, R contains one SCC.


   R
DPs
       →DP Problem 1
Narrowing Transformation


Dependency Pairs:

F(a, f(f(a, a), x)) -> F(a, x)
F(a, f(f(a, a), x)) -> F(a, f(a, x))
F(a, f(f(a, a), x)) -> F(f(a, a), f(a, f(a, x)))


Rule:


f(a, f(f(a, a), x)) -> f(f(a, a), f(a, f(a, x)))





On this DP problem, a Narrowing SCC transformation can be performed.
As a result of transforming the rule

F(a, f(f(a, a), x)) -> F(f(a, a), f(a, f(a, x)))
one new Dependency Pair is created:

F(a, f(f(a, a), f(f(a, a), x''))) -> F(f(a, a), f(a, f(f(a, a), f(a, f(a, x'')))))

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
Nar
           →DP Problem 2
Narrowing Transformation


Dependency Pairs:

F(a, f(f(a, a), f(f(a, a), x''))) -> F(f(a, a), f(a, f(f(a, a), f(a, f(a, x'')))))
F(a, f(f(a, a), x)) -> F(a, f(a, x))
F(a, f(f(a, a), x)) -> F(a, x)


Rule:


f(a, f(f(a, a), x)) -> f(f(a, a), f(a, f(a, x)))





On this DP problem, a Narrowing SCC transformation can be performed.
As a result of transforming the rule

F(a, f(f(a, a), x)) -> F(a, f(a, x))
one new Dependency Pair is created:

F(a, f(f(a, a), f(f(a, a), x''))) -> F(a, f(f(a, a), f(a, f(a, x''))))

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
Nar
           →DP Problem 2
Nar
             ...
               →DP Problem 3
Narrowing Transformation


Dependency Pairs:

F(a, f(f(a, a), f(f(a, a), x''))) -> F(a, f(f(a, a), f(a, f(a, x''))))
F(a, f(f(a, a), x)) -> F(a, x)
F(a, f(f(a, a), f(f(a, a), x''))) -> F(f(a, a), f(a, f(f(a, a), f(a, f(a, x'')))))


Rule:


f(a, f(f(a, a), x)) -> f(f(a, a), f(a, f(a, x)))





On this DP problem, a Narrowing SCC transformation can be performed.
As a result of transforming the rule

F(a, f(f(a, a), f(f(a, a), x''))) -> F(f(a, a), f(a, f(f(a, a), f(a, f(a, x'')))))
two new Dependency Pairs are created:

F(a, f(f(a, a), f(f(a, a), x'''))) -> F(f(a, a), f(f(a, a), f(a, f(a, f(a, f(a, x'''))))))
F(a, f(f(a, a), f(f(a, a), f(f(a, a), x')))) -> F(f(a, a), f(a, f(f(a, a), f(a, f(f(a, a), f(a, f(a, x')))))))

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
Nar
           →DP Problem 2
Nar
             ...
               →DP Problem 4
Forward Instantiation Transformation


Dependency Pairs:

F(a, f(f(a, a), f(f(a, a), f(f(a, a), x')))) -> F(f(a, a), f(a, f(f(a, a), f(a, f(f(a, a), f(a, f(a, x')))))))
F(a, f(f(a, a), f(f(a, a), x'''))) -> F(f(a, a), f(f(a, a), f(a, f(a, f(a, f(a, x'''))))))
F(a, f(f(a, a), x)) -> F(a, x)
F(a, f(f(a, a), f(f(a, a), x''))) -> F(a, f(f(a, a), f(a, f(a, x''))))


Rule:


f(a, f(f(a, a), x)) -> f(f(a, a), f(a, f(a, x)))





On this DP problem, a Forward Instantiation SCC transformation can be performed.
As a result of transforming the rule

F(a, f(f(a, a), f(f(a, a), x'''))) -> F(f(a, a), f(f(a, a), f(a, f(a, f(a, f(a, x'''))))))
no new Dependency Pairs are created.
The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
Nar
           →DP Problem 2
Nar
             ...
               →DP Problem 5
Forward Instantiation Transformation


Dependency Pairs:

F(a, f(f(a, a), f(f(a, a), x''))) -> F(a, f(f(a, a), f(a, f(a, x''))))
F(a, f(f(a, a), x)) -> F(a, x)
F(a, f(f(a, a), f(f(a, a), f(f(a, a), x')))) -> F(f(a, a), f(a, f(f(a, a), f(a, f(f(a, a), f(a, f(a, x')))))))


Rule:


f(a, f(f(a, a), x)) -> f(f(a, a), f(a, f(a, x)))





On this DP problem, a Forward Instantiation SCC transformation can be performed.
As a result of transforming the rule

F(a, f(f(a, a), f(f(a, a), f(f(a, a), x')))) -> F(f(a, a), f(a, f(f(a, a), f(a, f(f(a, a), f(a, f(a, x')))))))
no new Dependency Pairs are created.
The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
Nar
           →DP Problem 2
Nar
             ...
               →DP Problem 6
Remaining Obligation(s)




The following remains to be proven:
Dependency Pairs:

F(a, f(f(a, a), x)) -> F(a, x)
F(a, f(f(a, a), f(f(a, a), x''))) -> F(a, f(f(a, a), f(a, f(a, x''))))


Rule:


f(a, f(f(a, a), x)) -> f(f(a, a), f(a, f(a, x)))




Termination of R could not be shown.
Duration:
0:00 minutes