Termination Proof Script

Consider the TRS R consisting of the rewrite rules
1:    app(f,app(f,x))  → app(g,app(f,x))
2:    app(g,app(g,x))  → app(f,x)
There are 2 dependency pairs:
3:    APP(f,app(f,x))  → APP(g,app(f,x))
4:    APP(g,app(g,x))  → APP(f,x)
Consider the SCC {3,4}. By taking the AF π with π(APP) = 2 and π(app) = [2] together with the lexicographic path order with empty precedence, the rules in {1,3} are weakly decreasing and the rules in {2,4} are strictly decreasing. Hence the TRS is terminating.
Tyrolean Termination Tool  (0.01 seconds)   ---  May 3, 2006