code: def pslash(p):
      p1, p2, p3 = p
      p0 = sqrt(m**2 + p1**2 + p2**2 + p3**2)
      return gamma0 * p0 - gamma1 * p1 - gamma2 * p2 - gamma3 * p3
  
file_path: sympy/examples/advanced/qft.py
imports: from sympy import Basic, Symbol, Matrix, ones, sqrt, pprint, Eq, sympify
  from sympy.physics import msigma, mgamma
label_desc: Use image node_id 3 for calling a global function with example usage: pslash(p) and returns: unknown