mathlib3

27cd5c11 - feat(group_theory/{perm/cycle_type, specific_groups/alternating_group}): the alternating group is generated by 3-cycles (#6949)

feat(group_theory/{perm/cycle_type, specific_groups/alternating_group}): the alternating group is generated by 3-cycles (#6949) Moves the alternating group to a new file, renames `alternating_subgroup` to `alternating_group` Proves that any permutation whose support has cardinality 3 is a cycle Defines `equiv.perm.is_three_cycle` Shows that the alternating group is generated by 3-cycles Co-authored-by: Aaron Anderson <65780815+awainverse@users.noreply.github.com> Co-authored-by: Thomas Browning <tb65536@uw.edu>