Property or link with union type of type and a derived type produces error

[dnwpark]

Given the schema

  type A;
  type A_ extending A;

  type Bad {
    property foo -> A | A_;
  };

The following error is produced:

SchemaError: object type 'default::A' already exists

Given the schema

  type A;
  type A_ extending A;
  type B;

  type Bad {
    property foo -> A | A_ | B;
  };

The following error is produced:

error: type 'default::(default:A | default:A_ | default:B)' does not exist
   │
22 │     property foo -> A | A_ | B;
   │                     ^^^^^^^^^^ error