W1 = W2 :true if for the two quotient spaces W1 = V1 / U1 and
W2 = V2 / U2 the equalities V1 = V2 and U1 = U2
hold, and false otherwise.
W1 < W2 :true if for the two quotient spaces W1 = V1 / U1 and
W2 = V2 / U2 either U1 < U2 or U1 = U2 and
V1 < V2 hold, and false otherwise.
GAP 3.4.4