There may be multiple subgroups that are pairwise permutable complements

From Groupprops

Statement

Let be any natural number. Then, there exists a finite group with subgroups such that and are Permutable complements (?) in for any .

Proof

Let be a prime such that . Let be the group : in other words, is an elementary Abelian group of order . has cyclic subgroups of order , and any two of these are permutable complements.