code: def irep_pm(p, n):
      """
      Calculate pruning measure for IREP*
      """
      # p + n == 0 is meaningless
      if p + n == 0:
          return -2.0
      else:
          return (p - float(n)) / (p + float(n))
  
file_path: AIX360/aix360/algorithms/rule_induction/ripper/pruning.py
imports: import numba
  import numpy
  from aix360.algorithms.rule_induction.ripper.binding import _rule_predict, _rule_list_predict
  from aix360.algorithms.rule_induction.ripper.mdl import _mdl
label_desc: Use image node_id 2 for calling a global function with example usage: irep_pm(p, n) and returns: unknown, unknown