(VAR v x y z )
(RULES 
        h(x, x) -> h(a, b)
        g(g(x, a), y) -> g(g(a, y), g(a, x))
        f(g(x, y)) -> g(g(f(f(y)), h(a, a)), x)
        h(h(f(f(x)), y), h(z, v)) -> h(h(f(z), f(f(f(y)))), h(v, x))
        
)