Note that R1 and R2 produce a new derivation for the original sentence, whereas R3 and R4 produce a derivation that yields a permutation of that sentence: The order of the substrings corresponding to the categories Z and X/Y (in the case of rule R3) or X /Y (in the case of rule R4) is reversed.
r3 captures the relation between the two derivations of Swiss German word orders shown in Figure 11: Applying r3 to derivation (5) gives derivation (6).