code: def log(val):
      """return -inf for log(0) instead of throwing error like python implementation does it"""
      if val > 0:
          return math.log(val)
      return float("-inf")
  
file_path: calamari/calamari_ocr/ocr/model/ctcdecoder/token_passing_ctc_decoder.py
imports: import math
  import numpy
  from calamari_ocr.ocr.model.ctcdecoder.ctc_decoder import CTCDecoder
label_desc: Use image node_id 4 for calling a global function with example usage: log(val) and returns: float, math