be a multiple of(The integer b is a multiple of the integer a if there is an integer d such that b = da. • Говорят, что число a кратно числу b, если a делится на b без остатка.Alexander Demidov)
k-fold rotation through an angle of(consider (the) invariant points of the compound transformation TnRk, where Rk denotes k-fold rotation through an angle of 2n)
