' * ' . !•«•» there is at least one point of X In each A±. Then. If for al lA^l. ** 4a , the order of ♦ la * m. Corr.: If R - AjU ... UA , the order of 1 la at laaat &r. The retina is a square array … Fig. 3.2 Proof; For each i “ 1, m let 6^ be the group of penetrations of 1 which permutes the elements of At but do not affect the elements of the I complement of A^. Let G be the group generated by ail elements of the G^. Clearly t i« invariant with respect to G. Let * be the set of masks of…
