Term Rewriting System R:
[x]
app(g, app(h, app(g, x))) -> app(g, x)
app(g, app(g, x)) -> app(g, app(h, app(g, x)))
app(h, app(h, x)) -> app(h, app(app(f, app(h, x)), x))

Termination of R to be shown.



   R
Dependency Pair Analysis



R contains the following Dependency Pairs:

APP(g, app(g, x)) -> APP(g, app(h, app(g, x)))
APP(g, app(g, x)) -> APP(h, app(g, x))
APP(h, app(h, x)) -> APP(h, app(app(f, app(h, x)), x))
APP(h, app(h, x)) -> APP(app(f, app(h, x)), x)
APP(h, app(h, x)) -> APP(f, app(h, x))

Furthermore, R contains one SCC.


   R
DPs
       →DP Problem 1
Polynomial Ordering


Dependency Pairs:

APP(h, app(h, x)) -> APP(app(f, app(h, x)), x)
APP(h, app(h, x)) -> APP(h, app(app(f, app(h, x)), x))
APP(g, app(g, x)) -> APP(h, app(g, x))
APP(g, app(g, x)) -> APP(g, app(h, app(g, x)))


Rules:


app(g, app(h, app(g, x))) -> app(g, x)
app(g, app(g, x)) -> app(g, app(h, app(g, x)))
app(h, app(h, x)) -> app(h, app(app(f, app(h, x)), x))





The following dependency pair can be strictly oriented:

APP(h, app(h, x)) -> APP(app(f, app(h, x)), x)


Additionally, the following rules can be oriented:

app(g, app(h, app(g, x))) -> app(g, x)
app(g, app(g, x)) -> app(g, app(h, app(g, x)))
app(h, app(h, x)) -> app(h, app(app(f, app(h, x)), x))


Used ordering: Polynomial ordering with Polynomial interpretation:
  POL(g)=  1  
  POL(h)=  1  
  POL(app(x1, x2))=  0  
  POL(f)=  0  
  POL(APP(x1, x2))=  x1  

resulting in one new DP problem.



   R
DPs
       →DP Problem 1
Polo
           →DP Problem 2
Dependency Graph


Dependency Pairs:

APP(h, app(h, x)) -> APP(h, app(app(f, app(h, x)), x))
APP(g, app(g, x)) -> APP(h, app(g, x))
APP(g, app(g, x)) -> APP(g, app(h, app(g, x)))


Rules:


app(g, app(h, app(g, x))) -> app(g, x)
app(g, app(g, x)) -> app(g, app(h, app(g, x)))
app(h, app(h, x)) -> app(h, app(app(f, app(h, x)), x))





Using the Dependency Graph the DP problem was split into 2 DP problems.


   R
DPs
       →DP Problem 1
Polo
           →DP Problem 2
DGraph
             ...
               →DP Problem 3
Polynomial Ordering


Dependency Pair:

APP(h, app(h, x)) -> APP(h, app(app(f, app(h, x)), x))


Rules:


app(g, app(h, app(g, x))) -> app(g, x)
app(g, app(g, x)) -> app(g, app(h, app(g, x)))
app(h, app(h, x)) -> app(h, app(app(f, app(h, x)), x))





The following dependency pair can be strictly oriented:

APP(h, app(h, x)) -> APP(h, app(app(f, app(h, x)), x))


Additionally, the following rules can be oriented:

app(g, app(h, app(g, x))) -> app(g, x)
app(g, app(g, x)) -> app(g, app(h, app(g, x)))
app(h, app(h, x)) -> app(h, app(app(f, app(h, x)), x))


Used ordering: Polynomial ordering with Polynomial interpretation:
  POL(g)=  1  
  POL(h)=  1  
  POL(app(x1, x2))=  x1  
  POL(f)=  0  
  POL(APP(x1, x2))=  x2  

resulting in one new DP problem.



   R
DPs
       →DP Problem 1
Polo
           →DP Problem 2
DGraph
             ...
               →DP Problem 5
Dependency Graph


Dependency Pair:


Rules:


app(g, app(h, app(g, x))) -> app(g, x)
app(g, app(g, x)) -> app(g, app(h, app(g, x)))
app(h, app(h, x)) -> app(h, app(app(f, app(h, x)), x))





Using the Dependency Graph resulted in no new DP problems.


   R
DPs
       →DP Problem 1
Polo
           →DP Problem 2
DGraph
             ...
               →DP Problem 4
Polynomial Ordering


Dependency Pair:

APP(g, app(g, x)) -> APP(g, app(h, app(g, x)))


Rules:


app(g, app(h, app(g, x))) -> app(g, x)
app(g, app(g, x)) -> app(g, app(h, app(g, x)))
app(h, app(h, x)) -> app(h, app(app(f, app(h, x)), x))





The following dependency pair can be strictly oriented:

APP(g, app(g, x)) -> APP(g, app(h, app(g, x)))


Additionally, the following rules can be oriented:

app(g, app(h, app(g, x))) -> app(g, x)
app(g, app(g, x)) -> app(g, app(h, app(g, x)))
app(h, app(h, x)) -> app(h, app(app(f, app(h, x)), x))


Used ordering: Polynomial ordering with Polynomial interpretation:
  POL(g)=  1  
  POL(h)=  0  
  POL(app(x1, x2))=  x1  
  POL(f)=  0  
  POL(APP(x1, x2))=  1 + x2  

resulting in one new DP problem.


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