(VAR X )
(STRATEGY CONTEXTSENSITIVE
        (f 1) 
        (0 ) 
        (cons 1) 
        (s 1) 
        (p 1) 
)
(RULES 
        f(0) -> cons(0, f(s(0)))
        f(s(0)) -> f(p(s(0)))
        p(s(X)) -> X
        
)