摘要
良结构下推系统是下推系统和良结构迁移系统的结合,该系统允许状态和栈字符是向量的形式,因而它们是无限的.状态迁移的同时允许栈进行入栈出栈的操作.它"非常接近不可判定的边缘".利用重置0操作,提出了一种模型可覆盖性问题复杂度下界的一般性证明方法,并且证明了状态是三维向量的子集和一般性的良结构下推系统的可覆盖性问题分别是Tower难和Hyper-Ackermann难的.
Well-Structured pushdown systems （WSPDSs） combine pushdown systems and well-structured transition systems to allow locations and stack alphabets to be vectors, and thus they are unbounded. States change with the push and pop operations on the stack. The model has been said to be ＂very close to the border of undecidability＂. This paper proposes a general framework to get the lower bounds for coverability complexity of a model by adopting the reset-zero method. The paper proves that the complexity is Tower-hard when a WSPDS is restricted with three dimensional state vectors, and H^er-Ackermann hard for the ~eneral WSPDSs.
作者
李春淼
蔡小娟
李国强
LI Chun-Miao;CAI Xiao-Juan;LI Guo-Qiang(School of Software,Shanghai Jiaotong University,Shanghai 200240,China)
出处
《软件学报》
EI
CSCD
北大核心
2018年第10期3009-3020,共12页
Journal of Software
基金
国家自然科学基金(61472238
61672340
61872232)~~
