docs: def convert_pronouns( mrf_lines ):
      ''' Converts pronouns (analysis lines with '_P_') from Filosoft's mrf to 
          syntactic analyzer's mrf format;
          Uses the set of predefined pronoun conversion rules from _pronConversions;
          
          _pronConversions should be a list of lists, where each outer list stands 
          for a single conversion rule and inner list contains a pair of elements:
          first is the regexp pattern and the second is the replacement, used in
             re.sub( pattern, replacement, line )
          
          Returns the input mrf list, with the lines converted from one format
          to another;
      ''' 
      i = 0
      while ( i < len(mrf_lines) ):
          line = mrf_lines[i]
          if '_P_' in line:  # only consider lines containing pronoun analyses
             for [pattern, replacement] in _pronConversions:
                 lastline = line
                 line = re.sub(pattern, replacement, line)
                 if lastline != line:
                    mrf_lines[i] = line
                    break
          i += 1
      return mrf_lines