Universal quantifiers occur frequently in proof obligations produced by program verifiers, for instance, to axiomatize uninterpreted functions and to express properties of arrays. SMT-based verifiers typically reason about them via E-matching, an SMT algorithm that requires syntactic matching patterns to guide the quantifier instantiations. Devising good matching patterns is challenging. In particular, overly restrictive patterns may lead to spurious verification errors if the quantifiers needed for a proof are not instantiated; they may also conceal unsoundness caused by inconsistent axiomatizations. In this paper, we present the first technique that identifies and helps the users remedy the effects of overly restrictive matching patterns. We designed a novel algorithm to synthesize missing triggering terms required to complete a proof. Tool developers can use this information to refine their matching patterns and prevent similar verification errors, or to fix a detected unsoundness.

中文翻译：

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在基于SMT的程序验证程序中识别过于严格的匹配模式

通用量词经常出现在程序验证者产生的证明义务中，例如，公理化未解释的函数并表达数组的属性。基于SMT的验证程序通常会通过E-matching进行推理，E-matching是一种SMT算法，需要语法匹配模式来指导量词的实例化。设计良好的匹配模式具有挑战性。特别是，如果没有实例化证明所需要的量词，那么过于严格的模式可能会导致虚假的验证错误。它们也可能掩盖了不一致的公理化导致的声音不健全。在本文中，我们提出了第一种技术，该技术可以识别并帮助用户纠正过度限制的匹配模式的影响。我们设计了一种新颖的算法来合成完成证明所需的缺失触发项。