This equation can be written as = ,
which shows that, even though does not commute with elements of RC, it does
so at the cost of interchanging rows and columns. As a consequence, any symmetry that can be obtained by composing and elements of R C in any order can be
written in the form with 2 RC. (The same symmetry can also be written in
the form with 2 RC where and are the same except for the interchange
of rows and columns.)