In defeasible logic, there are three different types of propositions: strict rules specify that a fact is always a consequence of another; defeasible rules specify that a fact is typically a consequence of another; undercutting defeaters specify exceptions to defeasible rules.
弗? 兰 克? 凯 斯 # 口? 径 的 子?? 会 瞬? 间射 穿 墓碑 的LASER-wikipedia2 LASER-wikipedia2