Termination Proof Script

Consider the TRS R consisting of the rewrite rules
1:    x - 0  → x
2:    s(x) - s(y)  → x - y
3:    0 y  → true
4:    s(x) 0  → false
5:    s(x) s(y)  → x y
6:    if(true,x,y)  → x
7:    if(false,x,y)  → y
8:    perfectp(0)  → false
9:    perfectp(s(x))  → f(x,s(0),s(x),s(x))
10:    f(0,y,0,u)  → true
11:    f(0,y,s(z),u)  → false
12:    f(s(x),0,z,u)  → f(x,u,z - s(x),u)
13:    f(s(x),s(y),z,u)  → if(x y,f(s(x),y - x,z,u),f(x,u,z,u))
There are 10 dependency pairs:
14:    s(x) -# s(y)  → x -# y
15:    s(x) <=# s(y)  → x <=# y
16:    PERFECTP(s(x))  → F(x,s(0),s(x),s(x))
17:    F(s(x),0,z,u)  → F(x,u,z - s(x),u)
18:    F(s(x),0,z,u)  → z -# s(x)
19:    F(s(x),s(y),z,u)  → IF(x y,f(s(x),y - x,z,u),f(x,u,z,u))
20:    F(s(x),s(y),z,u)  → x <=# y
21:    F(s(x),s(y),z,u)  → F(s(x),y - x,z,u)
22:    F(s(x),s(y),z,u)  → y -# x
23:    F(s(x),s(y),z,u)  → F(x,u,z,u)
The approximated dependency graph contains 3 SCCs: {14}, {15} and {17,21,23}. Hence the TRS is terminating.
Tyrolean Termination Tool  (0.10 seconds)   ---  May 3, 2006