code: def p_Callable(p):
      '''
      Callable : NsContentName LPARENT
               | NsContentName SCOPEOP INDENTIFIER LPARENT
               | Expression LPARENT
               | STATIC SCOPEOP INDENTIFIER LPARENT
      '''
      if len(p) <= 3:
          p[0] = Callable(p[1], None)
      else:
          p[0] = Callable(p[1], p[3]f p_Callable(p):
      '''
      Callable : NsContentName LPARENT
               | NsContentName SCOPEOP INDENTIFIER LPARENT
               | Expression LPARENT
               | STATIC SCOPEOP INDENTIFIER LPARENT
      '''
      if len(p) <= 3:
          p[0] = Callable(p[1], None)
      else:
          p[0] = Callable(p[1], p[3])
docs: Callable : NsContentName LPARENT
               | NsContentName SCOPEOP INDENTIFIER LPARENT
               | Expression LPARENT
               | STATIC SCOPEOP INDENTIFIER LPARENT