code: def dummy_sgs(dummies, sym, n):
      """
      Return the strong generators for dummy indices.
  
      Parameters
      ==========
  
      dummies : List of dummy indices.
          `dummies[2k], dummies[2k+1]` are paired indices.
          In base form, the dummy indices are always in
          consecutive positions.
      sym : symmetry under interchange of contracted dummies::
          * None  no symmetry
          * 0     commuting
          * 1     anticommuting
  
      n : number of indices
  
      Examples
      ========
  
      >>> from sympy.combinatorics.tensor_can import dummy_sgs
      >>> dummy_sgs(list(range(2, 8)), 0, 8)
      [[0, 1, 3, 2, 4, 5, 6, 7, 8, 9], [0, 1, 2, 3, 5, 4, 6, 7, 8, 9],
       [0, 1, 2, 3, 4, 5, 7, 6, 8, 9], [0, 1, 4, 5, 2, 3, 6, 7, 8, 9],
       [0, 1, 2, 3, 6, 7, 4, 5, 8, 9]]
      """
      if len(dummies) > n:
          raise ValueError("List too large")
      res = []
      # exchange of contravariant and covariant indices
      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)
      # rename dummy indices
      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
  
imports: from sympy.combinatorics.permutations import Permutation, _af_rmul, _af_invert, _af_new
  from sympy.combinatorics.perm_groups import PermutationGroup, _orbit, _orbit_transversal
  from sympy.combinatorics.util import _distribute_gens_by_base, _orbits_transversals_from_bsgs
label_desc: Use image node_id 1 for calling a global function with example usage: dummy_sgs(dummies, sym, n) and returns: res