SCHEMA lists the tables of a PPA book, their keys and their core columns:
facts with one meaning each, typed and empty unless supplied. Every other
column is yours. relativities.Book(tables, schema=ppa.SCHEMA) is a PPA
book, a relativities.Study builds versions of it for what-if analysis, and
a relativities.Program rates it with one carrier’s rater: its prepare turns
the book into that rater’s input.
SCHEMA
Book(tables, schema=ppa.SCHEMA). print(ppa.SCHEMA) lists every column, and the PPA book schema page shows the same tables.