code: def test_equivalent_internal_lines_VT1T1_AT():
      i, j, k, l = symbols("i j k l", below_fermi=True, cls=Dummy)
      a, b, c, d = symbols("a b c d", above_fermi=True, cls=Dummy)
  
      exprs = [  # permute v.  Different dummy order. Not equivalent.
          atv(i, j, a, b) * att(a, i) * att(b, j),
          atv(j, i, a, b) * att(a, i) * att(b, j),
          atv(i, j, b, a) * att(a, i) * att(b, j),
      ]
      for permut in exprs[1:]:
          assert substitute_dummies(exprs[0]) != substitute_dummies(
              permut
          )
  
      exprs = [  # permute v.  Different dummy order. Equivalent
          atv(i, j, a, b) * att(a, i) * att(b, j),
          atv(j, i, b, a) * att(a, i) * att(b, j),
      ]
      for permut in exprs[1:]:
          assert substitute_dummies(exprs[0]) == substitute_dummies(
              permut
          )
  
      exprs = [  # permute t.  Same dummy order, not equivalent.
          atv(i, j, a, b) * att(a, i) * att(b, j),
          atv(i, j, a, b) * att(b, i) * att(a, j),
      ]
      for permut in exprs[1:]:
          assert substitute_dummies(exprs[0]) != substitute_dummies(
              permut
          )
  
      exprs = [  # permute v and t.  Different dummy order, equivalent
          atv(i, j, a, b) * att(a, i) * att(b, j),
          atv(j, i, a, b) * att(a, j) * att(b, i),
          atv(i, j, b, a) * att(b, i) * att(a, j),
          atv(j, i, b, a) * att(b, j) * att(a, i),
      ]
      for permut in exprs[1:]:
          assert substitute_dummies(exprs[0]) == substitute_dummies(
              permut
          )
  
imports: from sympy.physics.secondquant import Dagger, Bd, VarBosonicBasis, BBra, B, BKet, FixedBosonicBasis, matrix_rep, apply_operators, InnerProduct, Commutator, KroneckerDelta, AnnihilateBoson, CreateBoson, BosonicOperator, F, Fd, FKet, BosonState, CreateFermion, AnnihilateFermion, evaluate_deltas, AntiSymmetricTensor, contraction, NO, wicks, PermutationOperator, simplify_index_permutations, _sort_anticommuting_fermions, _get_ordered_dummies, substitute_dummies, FockStateBosonKet, ContractionAppliesOnlyToFermions
  from sympy.concrete.summations import Sum
  from sympy.core.function import Function, expand
  from sympy.core.numbers import I, Rational
  from sympy.core.singleton import S
  from sympy.core.symbol import Dummy, Symbol, symbols
  from sympy.functions.elementary.miscellaneous import sqrt
  from sympy.printing.repr import srepr
  from sympy.simplify.simplify import simplify
  from sympy.testing.pytest import slow, raises
  from sympy.printing.latex import latex
label_desc: Use image node_id 48 for calling a global function with example usage: test_equivalent_internal_lines_VT1T1_AT() without return types