







An experimental TypeSpec syntax for Lexicon
typelex – An experimental TypeSpec syntax for Lexicon
An experimental TypeSpec syntax for AT Protocol Lexicons. Write Lexicons in a more readable syntax using TypeSpec.

danabra.mov/resolve-lexicon
Resolve AT Lexicons over the network https://resolve-lexicon.pages.dev/
Syntax and semantics of dependent types
In this chapter we fix a particular syntax for a dependently typed calculus and define an abstract notion of model as well as a general interpretation function mapping syntactical objects to entities in a model. This interpretation function is shown to be sound with respect to the syntax.

Types and Programming Languages
A type system is a syntactic method for automatically checking the absence of certain erroneous behaviors by classifying program phrases according to the kinds of values they compute. The study of type systems--and of programming languages from a type-theoretic perspective -- -has important applications in software engineering, language design, high-performance compilers, and security. This text provides a comprehensive introduction both to type systems in computer science and to the basic theory of programming languages. The approach is pragmatic and operational; each new concept is motivated by programming examples and the more theoretical sections are driven by the needs of implementations. Each chapter is accompanied by numerous exercises and solutions, as well as a running implementation, available via the Web. Dependencies between chapters are explicitly identified, allowing readers to choose a variety of paths through the material. The core topics include the untyped lambda-calculus, simple type systems, type reconstruction, universal and existential polymorphism, subtyping, bounded quantification, recursive types, kinds, and type operators. Extended case studies develop a variety of approaches to modeling the features of object-oriented languages.

10 things I want to work on after the conference - Alex's Blog
a few people found this tool I made a while ago useful in @alex.bsky.team's lexicon workshop yesterday at #atmosphereconf, so resharing here for anyone else who wants to write their lexicons in typescript prototypey.org
generalized algebraic theory in nLab
A generalized algebraic theory (GAT, Cartmell 1978/86) is a dependent type theory in the syntactic sense: There are judgments declaring types and terms of types, where, critically, a type AA declared in context Γ\Gamma is allowed to depend on terms of Γ\Gamma. The only other judgments allowed are of equality (judgemental equality) of pairs of types or terms.
New Build Notes article discussing ATProto and how we as developers can go about forming standard lexicons for common datatypes without being overly prescriptive on implementation details that would limit creativity and competition blog.stygiantech.dev/a/3msmoumcr4d23-atproto-stand…
ATProto Standards Bodies—Guiding the Future of the Network
blog.stygiantech.deva few people found this tool I made a while ago useful in @alex.bsky.team's lexicon workshop yesterday at #atmosphereconf, so resharing here for anyone else who wants to write their lexicons in typescript prototypey.org