code: def short_form_filter(span: Span) -> bool:
      # All words are between length 2 and 10
      if not all([2 <= len(x) < 10 for x in span]):
          return False
  
      # At least 50% of the short form should be alpha
      if (sum([c.isalpha() for c in span.text]) / len(span.text)) < 0.5:
          return False
  
      # The first character of the short form should be alpha
      if not span.text[0].isalpha():
          return False
      return True
  
file_path: scispacy/scispacy/abbreviation.py
imports: from typing import Tuple, List, Optional, Set, Dict
  from collections import defaultdict
  from spacy.tokens import Span, Doc
  from spacy.matcher import Matcher
  from spacy.language import Language
label_desc: Use image node_id 4 for calling a global function with example usage: short_form_filter(span) and returns: True, False, False, False