code: def test_xy_dyad():
      N = ReferenceFrame("N")
      F = ReferenceFrame("F", indices=["1", "2", "3"])
      assert N.xy == Vector.outer(N.x, N.y)
      assert F.xy == Vector.outer(F.x, F.y)
  
imports: from sympy.core.numbers import pi
  from sympy.core.symbol import symbols
  from sympy.simplify import trigsimp
  from sympy.functions.elementary.trigonometric import cos, sin
  from sympy.matrices.dense import eye, zeros
  from sympy.matrices.immutable import ImmutableDenseMatrix
  from sympy.simplify.simplify import simplify
  from sympy.physics.vector import ReferenceFrame, Vector, CoordinateSym, dynamicsymbols, time_derivative, express, dot
  from sympy.physics.vector.frame import _check_frame
  from sympy.physics.vector.vector import VectorTypeError
  from sympy.testing.pytest import raises
  import warnings
  import pickle
label_desc: Use image node_id 31 for calling a global function with example usage: test_xy_dyad() without return types