P88i_forms_part_of should be subproperty of P89_falls_within: place X cannot be part of place Y, without X also falling withing Y.
From the scope notes of the two properties:
P89: addresses spatial containment only, and no ‘whole-part’ relationship between the two places is implied
P88: implies both spatial and contextual containment relationships between the two Places
If P88 means two things and P89 means one of them, then P88 must imply P89.
FORTH TR-429 (Apr 2012) "Fundamental Categories and Relationships for intuitive querying CIDOC-CRM based repositories"
http://www.cidoc-crm.org/docs/TechnicalReport429_April2012.pdf
says on p14 "P89F.falls_within is a super‐property of P88B.forms_part_of . P88 also defines contextual containment relationship between the Places. Here the more general relationship P89 is enough so we use this one in the path."
In accordance with this spec, I have implemented FRs about places (e.g. rso:FR7_from_place) using P89.
However, such subproperty statement is missing from CRM 5.0.4, cidoc_crm_v5.0.4_english_label.rdfs, and ecrm_current.owl.