symmetric group
Let be a set.Let be the set of permutations![]()
of (i.e. the set of bijective functions from to itself).Then the act of taking the composition
![]()
of two permutationsinduces a group structure
![]()
on .We call this group the symmetric group
![]()
.
The group is often denoted or .
is generated by the transpositions![]()
,and by any pair of a 2-cycle and -cycle.
is the Weyl group of the root system (and hence of the special linear group![]()
).