YES
Termination Proof
Termination Proof
by ttt2 (version ttt2 1.15)
Input
The rewrite relation of the following TRS is considered.
| 
a(x0) | 
→ | 
x0 | 
| 
a(a(x0)) | 
→ | 
b(c(x0)) | 
| 
a(b(b(x0))) | 
→ | 
b(b(a(a(x0)))) | 
Proof
1 Dependency Pair Transformation
          The following set of initial dependency pairs has been identified.
          
| 
a#(b(b(x0))) | 
→ | 
a#(x0) | 
| 
a#(b(b(x0))) | 
→ | 
a#(a(x0)) | 
1.1 Reduction Pair Processor with Usable Rules
        Using the linear polynomial interpretation over (4 x 4)-matrices with strict dimension 1 
            over the arctic semiring over the integers
| [c(x1)] | 
 =  | 
| 0 | 
0 | 
0 | 
0 | 
 
| 0 | 
0 | 
0 | 
0 | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
  · 
                    x1 + 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
 
 | 
| [a#(x1)] | 
 =  | 
| 0 | 
0 | 
                -∞
             | 
0 | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
  · 
                    x1 + 
| 0 | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
 
 | 
| [a(x1)] | 
 =  | 
| 0 | 
0 | 
0 | 
                -∞
             | 
 
| 0 | 
0 | 
0 | 
0 | 
 
| 0 | 
0 | 
0 | 
0 | 
 
| 0 | 
0 | 
0 | 
0 | 
 
  · 
                    x1 + 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 0 | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
 
 | 
| [b(x1)] | 
 =  | 
| 0 | 
0 | 
1 | 
0 | 
 
| 
                -∞
             | 
                -∞
             | 
0 | 
1 | 
 
| 
                -∞
             | 
0 | 
0 | 
0 | 
 
| 0 | 
                -∞
             | 
0 | 
0 | 
 
  · 
                    x1 + 
| 
                -∞
             | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 0 | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 0 | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
| 0 | 
                -∞
             | 
                -∞
             | 
                -∞
             | 
 
 
 | 
            together with the usable
            rules
| 
a(x0) | 
→ | 
x0 | 
| 
a(a(x0)) | 
→ | 
b(c(x0)) | 
| 
a(b(b(x0))) | 
→ | 
b(b(a(a(x0)))) | 
            (w.r.t. the implicit argument filter of the reduction pair),
          
	      all pairs could be removed.
	    1.1.1 P is empty 
There are no pairs anymore.