Termination Proof Script
Consider the TRS R consisting of the rewrite rules
 | 
| 1: | 
   | 
f(X) | 
 → cons(X,f(g(X))) | 
| 2: | 
   | 
g(0) | 
 → s(0) | 
| 3: | 
   | 
g(s(X)) | 
 → s(s(g(X))) | 
| 4: | 
   | 
sel(0,cons(X,Y)) | 
 → X | 
| 5: | 
   | 
sel(s(X),cons(Y,Z)) | 
 → sel(X,Z) | 
 | 
There are 4 dependency pairs:
 | 
| 6: | 
   | 
F(X) | 
 → F(g(X)) | 
| 7: | 
   | 
F(X) | 
 → G(X) | 
| 8: | 
   | 
G(s(X)) | 
 → G(X) | 
| 9: | 
   | 
SEL(s(X),cons(Y,Z)) | 
 → SEL(X,Z) | 
 | 
The approximated dependency graph contains 3 SCCs:
{8},
{6}
and {9}.
- 
Consider the SCC {8}.
There are no usable rules.
By taking the AF π with
π(G) = 1 together with
the lexicographic path order with
empty precedence,
rule 8
is strictly decreasing.
 
- 
Consider the SCC {6}.
The usable rules are {2,3}.
The constraints could not be solved.
 
- 
Consider the SCC {9}.
There are no usable rules.
By taking the AF π with
π(SEL) = 1 together with
the lexicographic path order with
empty precedence,
rule 9
is strictly decreasing.
 
Tyrolean Termination Tool  (0.01 seconds)
  ---  May 4, 2006