Scope
Argon is a programming language for declaring and reasoning over a richly-typed knowledge graph at the data-system layer. The canonical specification of the language core lives in Lean 4 under spec/lean/; this document specifies the surface in prose. Where they disagree, the Lean wins.
The language is built from five atoms — meta-calculus, constructs, rule, trait, macro — and nothing else. Every surface form lowers to one of them. Argon has no surface for IO, threads, network, or filesystem; those live in the host runtime. Tenancy and multi-tenant orchestration are application concerns, not language concerns.