PM-PRP-0030

A Property whose range is a Thing MUST be usable as the predicate of a Filter's proposition. Such a Property MUST NOT be required to declare an inverse.

Non-normative: PCIML has one Property construct doing two jobs — data slots that Restrictions read, and relationship predicates that Filters traverse. Nothing in the sources distinguishes them, and a tool almost certainly must, because the two are authored, validated and indexed differently. Whether Guil considered them one thing is Q-G-0036.

The "MUST NOT be required to declare an inverse" half matters more than it looks. The withdrawn PM-FLT-0030 assumed evaluation traverses the predicate inverse-wise from the transitioning object; PM-FLT-0080 withdrew that, so an engine cannot assume a single traversal direction and cannot demand owl:inverseOf on every relationship Property to get one.