(VAR x )
(RULES 
        a(b(x)) -> b(a(a(x)))
        b(c(x)) -> c(b(b(x)))
        c(a(x)) -> a(c(c(x)))
        u(a(x)) -> x
        v(b(x)) -> x
        w(c(x)) -> x
        a(u(x)) -> x
        b(v(x)) -> x
        c(w(x)) -> x
        
)