We show that an even
Kakutani equivalence class of ℤ2 actions is “spanned” by α and β equivalence classes
where α= {1 + α1,1 + α2}, β= {1 + β1,1 + β2} and {1,αi−1,βi−1} are rationally
independent for i = 1,2. Namely, given such vectors α and β and two evenly
Kakutani equivalent ℤ2 actions S and T, we show that U is α -equivalent to S and
β -equivalent to T.