All stages · Demo 428

Hungarian adószám

Choice hu / vat / other. Eight digits; 9-7-3-1 then 10−sum%10. Jev never mods 10. Seven digits need 8. Distinct from TAJ.

ChoiceADO 9-7-3 in JS

A digit tape. 12345676 books a NAV plate. A last-digit flip rejects. Seven digits never pass.

replaykind —ado —

STANDBY

All 4056 stages

Educational stage on jev.page — not the official TypeSafe console. Live calls go to POST https://api.typesafe.ai/v1/systemone from your browser when you paste a key. Without a key, the stage plays a recorded decision shaped like jev-1.13.0. Jev does not write the UI copy.