code: def p_next1(p):
      
      if p[1] == 'NEXT':
          p1 = make_nop()
          p3 = p[2]
      else:
          p1 = make_label(p[1], p.lineno(1))
          p3 = p[3]
  
      if p3 != gl.LOOPS[-1][1]:
          api.errmsg.syntax_error_wrong_for_var(p.lineno(2), gl.LOOPS[-1][1], p3)
          p[0] = make_nop()
          return
  
      p[0] = p1
docs: label_next : LABEL NEXT ID
                     | NEXT ID