Assume we have the following rules

(1) X + 0 ->> X

(2) M + N ->> P if P is M + N

(3) X * 0 ->> 0

(4) X * 1 ->> X

(5) M * N ->> P if P is M * N

(6) X = X ->> true

Which rules do you want to add to rewrite the term

(x * y) + z = z + (y * x)

to true?