Para-equestrian classification 4, 5, 6, 7, 12a/b, 13, 14, 21, 26a, 31a/b and 32 are allowed to have a whip which is held or used by a groom. Grade 1 drivers with Profiles 1, 2, 3, 4, 5, 6, 7, 9, 10a, 12a/b, 13, 14, 26a, 31a/b and 32 are allowed to have a brake operated by a groom. Grade 1 drivers with Profiles 1, 2, 3, 4, 5, 6, 7, 9, 10a, 12a/b, 13, 14, 26a, 31a/b and 32 are allowed to have a strap on feet or foot trough. Grade II is for riders who are higher functioning than Grade
9-orthoplex dual of the enneract with the C or [4,3] symmetry group, and a lower symmetry with two copies of 8-simplex facets, alternating, with the D or [3] symmetry group. Cartesian coordinates for the vertices of a 9-orthoplex, centered at the origin, are Every vertex pair is connected by an edge, except opposites. 9-orthoplex In geometry, a 9-orthoplex or 9-cross polytope, is a regular 9-polytope with 18 vertices, 144 edges, 672 triangle faces, 2016 tetrahedron cells, 4032 5-cells "4-faces", 5376 5-simplex "5-faces", 4608 6-simplex "6-faces", 2304 7-simplex "7-faces", and 512 8-simplex "8-faces". It has two constructed forms, the first being regular