def dummy_sgs(dummies, sym, n):
 if (len(dummies) > n):
  raise ValueError('List too large')
 res = []
 if (sym is not None):
  for j in dummies[::2]:
   a = list(range((n + 2)))
   if (sym == 1):
    a[n] = (n + 1)
    a[(n + 1)] = n
   (a[j], a[(j + 1)]) = (a[(j + 1)], a[j])
   res.append(a)
 for j in dummies[:(-3):2]:
  a = list(range((n + 2)))
  a[j:(j + 4)] = (a[(j + 2)], a[(j + 3)], a[j], a[(j + 1)])
  res.append(a)
 return res

def dummy_sgs ( dummies , sym , n ) : if ( len ( dummies ) > n ) : raise ValueError ( 'List too large' ) res = [ ] if ( sym is not None ) : for j in dummies [ : : 2 ] : a = list ( range ( ( n + 2 ) ) ) if ( sym == 1 ) : a [ n ] = ( n + 1 ) a [ ( n + 1 ) ] = n ( a [ j ] , a [ ( j + 1 ) ] ) = ( a [ ( j + 1 ) ] , a [ j ] ) res . append ( a ) for j in dummies [ : ( - 3 ) : 2 ] : a = list ( range ( ( n + 2 ) ) ) a [ j : ( j + 4 ) ] = ( a [ ( j + 2 ) ] , a [ ( j + 3 ) ] , a [ j ] , a [ ( j + 1 ) ] ) res . append ( a ) return res
return the strong generators for dummy indices parameters dummies : list of dummy indices dummies[2k] .