Gradual dependent types can help with the incremental adoption of dependently typed code by providing a principled semantics for imprecise and proofs, where some parts have been omitted. Current theories gradual types, though, lack central feature type theory: propositional equality. Lennon-Bertrand et al. show that, when reflexive proof refl is only closed value an equality type, extension Cal...

Separation logic is a spatial logic for reasoning locally about heap structures. A decidable fragment of its assertion language was presented in [1], based on a bounded model property. We exploit this property to give an encoding of this fragment into a first-order logic containing only the propositional connectives, quantification over the natural numbers and equality. This result is the first...

Modern processors have relatively simple specificationsbased on their instruction set architectures. Their implementations, however, are very complex, especially with the advent of performance-enhancing techniques such as pipelining, superscalar operation, and speculative execution. Formal techniques to verify that a processor implements its instruction set specification could yield more reliab...

Matching logic is a first-order logic (FOL) variant to reason about structure. Its sentences, called patterns, are constructed using variables, symbols, connectives and quantifiers, but no difference is made between function and predicate symbols. In models, a pattern evaluates into a power-set domain (the set of values that match it), in contrast to FOL where functions, predicates and connecti...

In the propositional modal (and algebraic) treatment of two-variable first-order logic equality is modelled by a ‘diagonal’ constant, interpreted in square products of universal frames as the identity (also known as the ‘diagonal’) relation. Here we study the decision problem of products of two arbitrary modal logics equipped with such a diagonal. As the presence or absence of equality in two-v...

We investigate a peculiar intuitionistic modal logic, called Propositional Lax Logic (PLL), which has promising applications to the formal veri cation of computer hardware. The logic has emerged from an attempt to express correctness `up to' behavioural constraints | a central notion in hardware veri cation | as a logical modality. As a modal logic it is special since it features a single modal...

There are several ways to extend the classical logical connectives for fuzzy truth degrees, in such a way that their behavior for the values 0 and 1 work exactly as in the classical one. For each extension of logical connectives the formulas which are always true (the tautologies) changes. In this paper we will provide a fuzzy interpretation for the usual connectives (conjunction, disjunction, ...