, 3 1 , 1 ] > ▁which ▁becomes ▁[ 4 , 3 , 3 ] ▁by ▁bis ect ing ▁the ▁fundamental ▁domain ▁by ▁a ▁mirror , ▁with ▁ 3 ▁orient ations ▁possible ; ▁and ▁the ▁full ▁extended ▁group ▁[ 3 [ 3 1 , 1 , 1 ]] ▁becomes ▁[ 3 , 4 , 3 ]. ▁▁ ▁The ▁ch iral ▁dem it esser actic ▁group ▁is ▁[ 3 1 , 1 , 1 ]+ ▁or ▁[ 1 + , 4 ,( 3 , 3 )+ ], ▁( ▁= ▁), ▁order ▁ 9 6 , ▁( D u ▁Val ▁# 2 2 ▁( T / V ; T / V ), ▁Con way ▁ ± 1 / 3 [ T × T ]). ▁This ▁group ▁leads ▁to ▁the ▁sn ub ▁ 2 4 - cell ▁with ▁construction ▁ ▁= ▁. ▁ ▁H ex ac os ich or ic ▁symmetry ▁▁ ▁H ex ac os ich or ic ▁group ▁– ▁H 4 , ▁[ 5 , 3 , 3 ], ▁( ), ▁order ▁ 1 4 4 0 0 , ▁( D u ▁Val ▁# 5 0 ▁( I / I ; I / I )* , ▁Con way ▁ ± [ I × I ]. 2 ), ▁named ▁for ▁the ▁ 6 0 0 - cell ▁( hex ac os ich or on ), ▁. ▁It ▁is ▁also ▁sometimes ▁called ▁the ▁hyper - icos ah ed ral ▁group ▁for ▁extending ▁the ▁ 3 D ▁ icos ah ed ral ▁group ▁[ 5 ,