Group
A group is a Monoid with the additional requirement that every element have an inverse. A group need not be commutative; this is a special case known as an Abelian group. group
- Inverse for each
there exists (provably unique) such that
Groups play an important role in describing Symmetry. The concept of a group may be generalised to the concept of a Groupoid, which can be thought of as a typed group.
Terminology and notation
Typically, given a group
- Both groups and group elements can be assigned order.
- A subset of a group that remains closed under the operation is a Subgroup.
is the trivial subgroup.