(VAR X )
(STRATEGY CONTEXTSENSITIVE
        (h 1) 
        (g 1) 
        (a ) 
        (f 1) 
        (b ) 
)
(RULES 
        h(X) -> g(X, X)
        g(a, X) -> f(b, X)
        f(X, X) -> h(a)
        a -> b
        
)