code: def l2_inner_product(a, b, lim):
      """
      Calculates the L2 inner product (a, b) over the domain lim.
      """
      return integrate(conjugate(a) * b, lim)
  
file_path: sympy/examples/advanced/gibbs_phenomenon.py
imports: from sympy import var, sqrt, integrate, conjugate, seterr, Abs, pprint, I, pi, sin, cos, sign, lambdify, Integral, S
label_desc: Use image node_id 2 for calling a global function with example usage: l2_inner_product(a, b, lim) and returns: integrate