code: def test_simplify():
      x, y = R2_r.coord_functions()
      dx, dy = R2_r.base_oneforms()
      ex, ey = R2_r.base_vectors()
      assert simplify(x) == x
      assert simplify(x * y) == x * y
      assert simplify(dx * dy) == dx * dy
      assert simplify(ex * ey) == ex * ey
      assert ((1 - x) * dx) / (1 - x) ** 2 == dx / (1 - x)
  
imports: from sympy.core import Lambda, Symbol, symbols
  from sympy.diffgeom.rn import R2, R2_p, R2_r, R3_r, R3_c, R3_s, R2_origin
  from sympy.diffgeom import Manifold, Patch, CoordSystem, Commutator, Differential, TensorProduct, WedgeProduct, BaseCovarDerivativeOp, CovarDerivativeOp, LieDerivative, covariant_order, contravariant_order, twoform_to_matrix, metric_to_Christoffel_1st, metric_to_Christoffel_2nd, metric_to_Riemann_components, metric_to_Ricci_components, intcurve_diffequ, intcurve_series
  from sympy.simplify import trigsimp, simplify
  from sympy.functions import sqrt, atan2, sin
  from sympy.matrices import Matrix
  from sympy.testing.pytest import raises, nocache_fail
  from sympy.testing.pytest import warns_deprecated_sympy
label_desc: Use image node_id 14 for calling a global function with example usage: test_simplify() without return types