Nit: Pinning and the discovered check are not really rules, but rather names of tactics.
At the "Is this move legal?" level, they don't need unique rules of its own if the lower-level rules are specified correctly.
"Look, if this guys TLA+ logic struggles to model a 1,500-year-old game without crying over a French pawn-capture rule, you can't expect me to integrate Stripe billing without a few state invariant violations."
unprovable•1h ago