(VAR x1 )
(RULES 
        r(e(x1)) -> w(r(x1))
        i(t(x1)) -> e(r(x1))
        e(w(x1)) -> r(i(x1))
        t(e(x1)) -> r(e(x1))
        w(r(x1)) -> i(t(x1))
        e(r(x1)) -> e(w(x1))
        r(i(t(e(r(x1))))) -> e(w(r(i(t(e(x1))))))
        
)