(VAR x y )
(STRATEGY OUTERMOST)
(RULES 
        f(g(x), h(x)) -> f(i(x), h(x))
        f(x, h(y)) -> f(x, j(y))
        f(i(x), h(x)) -> a
        f(x, j(y)) -> a
        i(x) -> g(x)
        j(x) -> h(x)
        
)