If two elements x and y belong to the same orbit, then their stabilizer subgroups, G x and G y , are isomorphic. More precisely: if y = g ⋅ ⋅ x , then G y = g G x g − − 1 . In the example this applies e.g. for 3 and 23, both reflection points. Reflection about 23 corresponds to a translation of −20, reflection about 3, and translation of 20.