Formal systems that describe computations over syntactic structures occur frequently in
computer science. Logic programming provides a natural framework for encoding and …

Abella [3] is an interactive system for reasoning about aspects of object languages that have
been formally presented through recursive rules based on syntactic structure. Abella utilizes …

Combining higher-order abstract syntax and (co)-induction in a logical framework is well
known to be problematic. We describe the theory and the practice of a tool called Hybrid …

Recursive relational specifications are commonly used to describe the computational
structure of formal systems. Recent research in proof theory has identified two features that …

This thesis concerns the development of a framework that facilitates the design and analysis
of formal systems. Specifically, this framework is intended to provide (1) a specification …

Proof search has been used to specify a wide range of computation systems. In order to
build a framework for reasoning about such specifications, we make use of a sequent …

When proof assistants and theorem provers implement the metatheory of logical systems,
they must deal with a range of syntactic expressions (eg, types, formulas, and proofs) that …

Proofs by logical relations play a key role to establish rich properties such as normalization
or contextual equivalence. They are also challenging to mechanize. In this paper, we …

Proofs with logical relations play a key role to establish rich properties such as normalization
or contextual equivalence. They are also challenging to mechanize. In this paper, we …

We formally verify in Abella that similarity in the call-by-name lambda calculus is a pre-
congruence, using Howe's method. This turns out to be a very challenging task for HOAS …