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Exactly since it declarative the style Lends itself using stored procedure calls to become composable

You cannot abstract over stored procedures either, so that's still not composable.

No idea what this means

Think of first-class functions. Can't do that with stored procedures, just like you can't do that with queries or tables in SQL.

Furthermore, stored procedures/functions are not queries.

Stored procedures can be relations. Queries are relations. Ergo, stored procedures can be queries.