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

Termination of R to be shown.



   R
Dependency Pair Analysis



R contains the following Dependency Pairs:

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

Furthermore, R contains one SCC.


   R
DPs
       →DP Problem 1
Semantic Labelling


Dependency Pair:

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


Rule:


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





Using Semantic Labelling, the DP problem could be transformed. The following model was found:
F(x0, x1)=  0
a=  1
f(x0, x1)=  1

From the dependency graph we obtain 1 (labeled) SCCs which each result in correspondingDP problem.


   R
DPs
       →DP Problem 1
SemLab
           →DP Problem 2
Modular Removal of Rules


Dependency Pair:

F11(a, f11(a, x)) -> F11(x, f11(a, f11(f11(a, a), a)))


Rules:


f11(a, f10(a, x)) -> f01(x, f11(a, f11(f11(a, a), a)))
f11(a, f11(a, x)) -> f11(x, f11(a, f11(f11(a, a), a)))





We have the following set of usable rules: none
To remove rules and DPs from this DP problem we used the following monotonic and CE-compatible order: Polynomial ordering.
Polynomial interpretation:
  POL(f_11(x1, x2))=  x1 + x2  
  POL(F_11(x1, x2))=  1 + x1 + x2  
  POL(a)=  0  

We have the following set D of usable symbols: {f11, F11, a}
No Dependency Pairs can be deleted.
2 non usable rules have been deleted.

The result of this processor delivers one new DP problem.



   R
DPs
       →DP Problem 1
SemLab
           →DP Problem 2
MRR
             ...
               →DP Problem 3
Unlabel


Dependency Pair:

F11(a, f11(a, x)) -> F11(x, f11(a, f11(f11(a, a), a)))


Rule:

none





Removed all semantic labels.

   R
DPs
       →DP Problem 1
SemLab
           →DP Problem 2
MRR
             ...
               →DP Problem 4
Instantiation Transformation


Dependency Pair:

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


Rule:

none





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

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

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

The transformation is resulting in no new DP problems.


Termination of R successfully shown.
Duration:
0:00 minutes