Compiler validation via equivalence modulo inputs

Confluence Modulo Equivalence in Constraint Handling Rules

Previous results on confluence for Constraint Handling Rules, CHR, are generalized to take into account user-defined state equivalence relations. This allows a much larger class of programs to enjoy the advantages of confluence, which include various optimization techniques and simplified correctness proofs. A new operational semantics for CHR is introduced that reduces notational overhead sign...

On Observational Equivalence and Compiler Correctness

We study the problem of giving proofs of compiler correctness in the framework of observational equivalence 16] and correspondences 17]. The starting point for correctness is a formal semantics of the programming language given in a form of Structural Operational Semantics 15] wich we call Relational Semantics 4, Chapter 2]. We start by introducing Relational Semantics. We then deene an equival...

Black-Box Equivalence Checking Across Compiler Optimizations

Equivalence checking is an important building block for program synthesis and verification. For a synthesis tool to compete with modern compilers, its equivalence checker should be able to verify the transformations produced by these compilers. We find that the transformations produced by compilers are much varied and the presence of undefined behaviour allows them to produce even more aggressi...

Automated verification of equivalence properties in cryptographic protocols modulo AC

The Quotient Algebra of Labeled Forests Modulo h-Equivalence

We introduce and study some natural operations on the structure of finite labeled forests which is of central interest for extending the difference hierarchy to the case of partitions. It is shown that the corresponding quotient-algebra modulo the so called h-equivalence is the simplest nontrivial semilattice with discrete closures. The algebra is also characterized as a free algebra in some qu...