code: def burr12_pdf(x, cc, dd):
      if x > 0:
          lx = math.log(x)
          logterm = math.log1p(math.exp(cc * lx))
          return math.exp(
              (cc - 1) * lx - (dd + 1) * logterm + math.log(cc * dd)
          )
      else:
          return 0
  
imports: import math
  import numbers
  import numpy
  from scipy import stats
  from scipy import special
  from ._qmc import check_random_state, Halton, QMCEngine
  from ._unuran.unuran_wrapper import NumericalInversePolynomial
  from scipy._lib._util import check_random_state
label_desc: Use image node_id 9 for calling a global function with example usage: burr12_pdf(x, cc, dd) and returns: math, int