mathlib

a6c82afb - feat(group_theory/specific_groups/*): computes the exponents of the dihedral and generalised quaternion groups (#11166)

feat(group_theory/specific_groups/*): computes the exponents of the dihedral and generalised quaternion groups (#11166) This PR shows that the exponent of the dihedral group of order `2n` is equal to `lcm n 2` and that the exponent of the generalised quaternion group of order `4n` is `2 * lcm n 2` Co-authored-by: Eric Rodriguez <ericrboidi@gmail.com> Co-authored-by: Julian-Kuelshammer <68201724+Julian-Kuelshammer@users.noreply.github.com>