Inversion symmetry (2D)

A1×A1+, also know as essic symmetry or chiral digonal symmetry, is a 2D spherical Coxeter group. It is the symmetry group of the parallelogram and corresponds to central inversion symmetry. It can be considered the digonal member of the family of chiral polygonal symmetries. It is a subsymmetry of any even polygonal symmetry.

Subgroups

 * I×I