Show HN: Lean4 proof that SSOT requires definition-time hooks and introspection
via news.ycombinator.com
Short excerpt below. Read at the original source.
I formalized the Single Source of Truth (SSOT) principle in Lean 4 (~2.1k LOC, zero sorry) and proved two core results: Structural SSOT is achievable only when a language provides definition-time hooks and runtime introspection. Macros/codegen (before definition) and reflection (after definition) are insufficient. These requirements are derived, not chosen: because structural facts are fixed […]