High Quality Content by WIKIPEDIA articles! In mathematics, specifically in the area of abstract algebra known as group theory, a semidirect product is a particular way in which a group can be put together from two subgroups, one of which is a normal subgroup. A semidirect product is a generalization of a direct product. A semidirect product is a cartesian product as a set, but with a particular multiplication operation. If G is the semidirect product of the normal subgroup N and the subgroup H, and both N and H are finite, then the order of G equals the product of the orders of N and H. Note that, as opposed to the case with the direct product, a semidirect product of two groups is not, in general, unique; if G and G? are two groups which both contain isomorphic copies of N as a normal subgroup and H as a subgroup, and both are a semidirect product of N and H, then it does not follow that G and G? are isomorphic. This remark leads to an extension problem, of describing the possibilities.

Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.