Gabriel Dos Reis via SG15 <sg15_at_[hidden]> writes:

> How would a program observe that an implementation partition isn't
> imported but is relevant to the behavior of the entire program?

The implementation partition can register itself (as part of the
static initialization) in some registry.

For example, the implementation partition may include a unit test
(because that's the only way to access the private parts) which
is registered with the test harness.