Tianyi Liang

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An increasing number of applications in verification and security rely on or could benefit from automatic solvers that can check the satisfiability of constraints over a rich set of data types that includes character strings. Unfortunately, most string solvers today are standalone tools that can reason only about (some fragment) of the theory of strings and(More)
We prove that the quantifier-free fragment of the theory of character strings with regular language membership constraints and linear integer constraints over string lengths is decidable. We do that by describing a sound, complete and terminating tableaux calculus for that fragment which uses as oracles a decision procedure for linear integer arithmetic and(More)
To my mother Chen Xingzhen. ii ACKNOWLEDGEMENTS I would like to thank first of all my thesis advisor, Prof. Aaron Stump. Five years ago when I applied for graduate school, I asked him for recommendation on books in logic. He suggested Girard's proofs and types to me. It is not an ordinary book in logic and it introduces me to the Girard's works on System F,(More)
<b>Motivation</b> The security of software is increasingly more critical for consumer confidence, protection of privacy, protection of intellectual property, and even national security. As threats to software security have become more sophisticated, so too have the techniques developed to ensure security. One basic technique that has become a fundamental(More)
Lambda encodings (such as Church encoding, Scott encoding and Parigot encoding) are methods to represent data in lambda calculus. Curry-Howard correspondence relates the formulas and proofs in intuitionistic logics to the types and programs in typed functional programming languages. Roughly speaking, Type theory (Intuitionistic Type Theory) formulates the(More)
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