“…b m,1 a m+1 f m+2,1 b −1 m,0 = 1, b m,0 f m+2,0 a −1 m+1 b −1 m,1 = 1, f m,0 c 3 b m+1,1 g m+2,3 b −1 m+1,0 c −1 3 = 1, f m,1 c 3 f m+1,0 a m+1 g m+2,3 b −1 m+1,1 c −1 3 = 1. g m,i c i+1 c i g m+2,i+1 c −1 i c −1 i+1 = 1, g m,i c i+1 a −1 m c i a m+1 g m+2,i+1 a −1 m+1 c −1 i a m c −1 i+1 = 1. Similar to the group W B ′ 4, the firs for relations are equivalent to the relations g m+2,3 = f −1 m+2 f m+1 c −1 3 f m c 3 f −1 m+1 , a m = f m f m+1 . Hence, the additional relations of W B ′ n , ≥ 5 have the form g m+2,3 = f −1 m+2 f m+1 c −1 3 f m c 3 f −1 m+1 , a m = f m f m+1 , g m,i c i+1 c i g m+2,i+1 c −1 i c −1 i+1 = 1,…”