Vietnamese legal & tax language

Vietnamese law changes quickly. A tax question asked today may depend on a decree that amended another decree last month, and a question about last year's tax settlement needs the rules that applied last year. We build the pieces that make answers checkable: • A library of laws, decrees, circulars and resolutions collected from official sources such as the Official Gazette (Công báo) and the Government portal, split into articles and numbered clauses so a single clause can be found. • Document lifecycles: when each document takes effect, what it replaces, repeals or amends, read from its own "Hiệu lực thi hành" article and title, rated clear or unclear and reviewed by people. • Search "as of" a date: documents not in force on that date rank lower, and a replaced document brings its successor. • Reading real files: scanned PDFs, digitally signed PDFs whose stamps hide the text layer, and tables. The result powers eChat's tax and law assistants, which answer with the document number, article and effective date so people can check them.