If H ≤ G and a and b belong to G, then
(1)
(2) aH = H if and only if
(3) aH = bH or aH ∩ bH = Ø
(4) aH = bH if and only if
(5) |aH| = |bH|
(6) aH = Ha if and only if H = aHa-1
(7) aH ≤ G if and only if