Armin Biere
Institute for Formal Models and Verification Johannes Kepler University Linz
作者Armin Biere是求解器业界大牛，CaDiCal全面透彻地汇集sat求解的技术发展方向，不但集采众家之长不断将最新的技术环节比较累积，而且创新改进后不断提出阶段性总结。
2018年的版本在求解UNSAT方面有优势，2019年保持了UNSAT方面的领先优势的同时追上来求解SAT样例的最先进水平。
1.对sat和unsat采用分开的决策队列（SEPARATE DECISION QUEUE）
The “default” configuration alternates stable and unstable phases, while the “unsat” configuration remains in the unstable search phase and the “sat” configuration vice versa only in the “stable” phase.
译文：“默认”配置将交替出现稳定和不稳定阶段：“unsat”配置将保留在不稳定搜索阶段；“sat”配置将只保留在“稳定”阶段。
The earlier versions of C A D I C A L already partially followed
the advice given by Chanseok Oh in [5] to interleave (what
we call) stable search phases focusing on satisfiable instances
with almost no restarts and (again in our terminology) unstable
search phases with the usual frequent but limited restarts
schedule. In our new version we use a reluctant doubling
scheme with base conflict interval 1024 for the stable phase.
稳定的搜索阶段，主要关注满足的实例，几乎不需要重新启动；不稳定的搜索阶段，通常是频繁但有限的重新启动计划。
译文：在我们的新版本中，我们使用了一种不情愿的倍增方案，在稳定阶段使用基础冲突间隔1024。
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However, the results of [5] also suggest to use a smoother
increase of scores for the stable phase using a separate decision
queue. We have integrated this idea. It required to add the usual
exponential VSIDS scoring mechanism using a binary heap as
in M INI SAT [6]. Thus this new version relies on its previous
VMTF queue [7] only for the unstable search phases and on
the exponential VSIDS for the stable search phase.
译文：然而，[5]的结果也建议在稳定阶段使用单独的决策队列平稳地增加分数。
译文：我们已经整合了这个想法。
译文：它需要使用一个二进制堆添加通常的指数VSIDS评分机制，如M INI SAT[6]。
因此，这个新版本依赖于以前的版本VMTF仅在不稳定搜索阶段对[7]进行排队，在稳定搜索阶段对指数vsid进行排队。
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2.组合了SLS求解器YalSAT