[DM] MS-DM-LC2-039

Section 3.3.1 Mapping PSVI Additions to Types
Technical

The rules about inferring type annotations seems to break named typing
in the context of union types.

The instance type of the element needs to be the name of the union type
and not the name of the member type that matches the instance's type.
Otherwise

$n instance of element(*, uniontype)

Will fail.