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Introduction

OWLIM Rules and Reasoning Dialect

RS3.1 FRs were implemented using reasoning dialect "OWL RL (optimized)", i.e. builtin_owl2-rl.pie.
We used constructs owl:PropertyChainAxiom, owl:TransitiveProperty, owl:ReflexiveProperty, and rdfs:subPropertyOf (which amounts to disjunction).
But as described in OWLIM Rules vs OWL RL#Less Expressive, OWL RL is less expressive than OWLIM Rules, since one cannot define a property by conjunction.
We are pretty sure the full FR set will require conjunction, so we'll go with OWLIM Rules. See OWLIM Rules documentation.

We'll use the RDFS reasoning dialect as a basis, by weaving our rules into builtin_RdfsRules.pie. That file is part of the OWLIM distribution, in my case
c:\my\Onto\proj\OWLIM\software\owlim-se-4.2.3924\builtin_RdfsRules.pie

Weaving for Production

This page is used to generate OWLIM artefacts for production. We "weave" them from {code} blocks in the page, following Literate Programming. We weave several files based on code block titles:

Title	Weaved into
Turtle	(not yet implemented) FR.ttl, The old file RF.ttl will be deleted from svn
Prefices	builtin_RdfsRules.pie, at the beginning of section Prefices (after the opening brace)
Axioms	builtin_RdfsRules.pie, at the beginning of section Axioms (after the opening brace)
Rule	builtin_RdfsRules.pie, at end of file (before the closing brace)
Rules	same place, but these are shorthand rules (see below)

• the weaver automatically generates rule identifiers in the form "Id: fr$n" where $n is a counter
• "Rule" includes one rule per code block in the OWLIM notation, eg:
• "Rules" includes one rule per line in a shorthand notation, eg:

  The shortcut notation is translated to the OWLIM notation. This shortcut form is very useful for shorter rules

Rule Validation

In addition to weaving FR-implementation.pie, the script performs rule validation: for each rule, checks that variables are used in a "linear" fashion, eg

Variables on the LHS should form a chain, with possible type-check branches.
The RHS should use the first and last var in the same order

Modularity and Naming

A very important aspect of our implementation is modularity: we define appropriate sub-FRs and use them when defining FRs.
We use the Erlangen CRM (ECRM) naming variant (underscores instead of dots), and the following naming conventions:

• crm: Enn_entity_name, crm: Pnn_property_name: CRM entities and properties
• rso:FRnn_name: property representing an FR
  • rso stands for "RS ontology"
  • nn is a number that we try to keep the same as a related CRM property number (eg FR7_thing_from_place is numbered after P7_took_place_at)
• rso:FRXnn_name: property representing a sub-FR
  • if the sub-FR is a disjunction of several CRM properties, we mention all numbers
    FRX_62_67 := P62_depicts or P67_refers_to
• rso:FRTnn_name: transitive closure of crm: Pnn_name
  • we denote this as FRTnn_name := Pnn_name+
• rso:FRSTnn_name: symmetric-transitive closure of crm: Pnn_name
  • we denote this as FRSTnn_name := (Pnn_name or Pnni_inverse_name)+
• rso:FCnn_name: Fundamental Concept or another class used in defining FRs

FR Dependency Graph

FR-weave.pl also generates a dependency graph showing which CRM props and sub-FRs are used in the implementation of each FR.

• This lets you see which CRM properties are "bundled" into which FRs. Similar info about the old implementation is at FR Implementation-old#FR Summary (Short Variant) or FR Implementation-old#FR Summary (Long Variant)
• It was an indispensable debugging aid while creating th FRs.

FR-graph.gv is processed with graphviz dot to create FR-graph.png:

Prefixes

This would add prefixes to FR.ttl (but we don't use such file):

This adds prefixes to the rules file (it already has: rdf rdfs owl xsd):

Transitive Properties

TransitiveProperty

owl:TransitiveProperty is a well-known OWL type stating that a property is transitive. ECRM declares the appropriate CRM properties as transitive, but for some reason it doesn't declare P9,P46 transitive (other "part of" properties, eg P106,P148 are transitive). I posted a bug to CRM SIG and fix it here:

The full list of transitive properties is:

• P9_consists_of, P9i_forms_part_of (ADDED)
• P10_falls_within, P10i_contains
• P46_is_composed_of, P46i_forms_part_of (ADDED)
• P86_falls_within, P86i_contains
• P88_consists_of, P88i_forms_part_of
• P89_falls_within, P89i_contains
• P106_is_composed_of, P106i_forms_part_of
• P114_is_equal_in_time_to
• P115_finishes, P115i_is_finished_by
• P116_starts, P116i_is_started_by
• P117_occurs_during, P117i_includes
• P120_occurs_before, P120i_occurs_after
• P127_has_broader_term, P127i_has_narrower_term
• P148_has_component, P148i_is_component_of

Note: we used to use owl:TransitiveProperty to make the transitive closure for some sub-FRs. But now we prefer to do it with explicit rules, since we want to always start at FC70_Thing, so as to eliminate useless triples

transitiveOver

ptop:transitiveOver is a useful generalization defined by the Proton Ontology. The semantics is defined with the following axiom:

(p,transitiveOver,q) (x,p,y) (y,q,z) => (x,p,z)

Sample usage is:

(locatedIn, transitiveOver, subRegionOf) (Ontotext,locatedIn,Bulgaria) (Bulgaria,subRegionOf,Europe) => (Ontotext,locatedIn,Europe)

We use this in FR-Transitive.ttl (described in FR Transitivity) to state that certain FRs are transitive over skos:broader.

We use the RDFS reasoning dialect as a basis, which implements rdfs:subClassOf and rdfs:subPropertyOf reasoning. To this we add relevant rules from builtin_owl2-rl.pie:

TODO: ptop:transitiveOver is more efficient than owl:TransitiveProperty since it uses only the step relation (eg skos:broader) but not its transitive closure (eg skos:broaderTransitive). Unfortunately CRM doesn't define step relations for its transitive properties.

Inverse Properties

Most CRM properties have an inverse, eg P110i_was_augmented_by is inverse of P110_augmented (Symmetric properties are their own inverse). ECRM declares all inverse properties as owl:inverseOf. Inverse reasoning is useful since it frees you from dependencies on how exactly the data is asserted:

Symmetric Properties

ECRM declares all CRM symmetric properties as owl:SymmetricProperty. ECRM always declares them as owl:inverseOf itself, so we don't need to treat them separately. Eg:

The full list of symmetric properties is:

• P69_is_associated_with
• P114_is_equal_in_time_to
• P121_overlaps_with
• P122_borders_with
• P132_overlaps_with
• P133_is_separated_from

No Reflexive Closure

FR definitions are full of reflexive-transitive sub-FRs. In FRThing.docx they are denoted (Pnnn)(0,n), and below we denote them as Pnn*. Eg

• x from z := x P74 y AND y P89* z

But it's bad style to use reflexive closure in the implementation since it generates lots of trivial facts (self-loops) in the semantic repository. Instead of reflexive closure, we use disjunction: the iterated property is applied 0 times in the first disjunct, and n times in the second, eg:

• x from z := x P74 z OR (x P74 y AND y P89+ z)

FR Notes

FR design in the following sections is based on FRThing.docx by M.Doerr and K.Tzompanaki, after clarifications and corrections by V.Alexiev.

• We don't implement FRs:
  • for which there is no data in neither Rembrandt nor BM collections
  • that are interesting for history/archaeology but not museum collections (eg Destroyed at)
  • that use the CRM Digital (CRMdig) extensions
• We omit composite FR such as "Was created/produced by person from" since they are treated separately
• In many cases we don't check types, since these are implied by the domain/range of a property. Eg in:
  • E24_Physical_Man-Made_Thing – P128_carries -> E73_Information_Object
    the property P128 implies that the source and target have the indicated types
• We check types (FC70_Thing) as early as possible to eliminate useless inferences
• We define FRs and sub-FRs using SPARQL Property Paths

Fundamental Concepts

Thing

FC70_Thing in General

"Thing" is defined as the following (was called C1.Object):

• FC70_Thing := E70_Thing NOT E21_Person NOT E55_Type NOT E30_Right NOT E41_Appellation

The concept of "NOT subclass" is not expressible with OWLIM rules:

• OWLIM rules can check != class, but not subclasses
• <owl:complementOf> and <owl:disjointWith> are used only for consistency checking (to infer a contradiction), not to define classes

I tried enumerating negative classes:

But that doesn't work (even if I enumerate all negative subclasses), since an E21_Person (negative) is also an E19_Physical_Object (positive), and we want E19.
Enumerating positive classes doesn't work either, for the same reason.

So FC70 would need to be implemented in SPARQL, eg

FC70_Thing and FR_dataset for RS

In RS we compute a dataset, which is important to select the right RForm; and to display a Dataset facet in the RS search. We now have 3 datasets (RKD, BM, YCBA):

• RKD data includes sub-objects (eg related/n is a related work, part/n is a frame that is part of a painting) that we can't display, so we introduced an extension sub-class rso:E22_Museum_Object. Because Rembrandt paintings come from different places, RKD data has varying keepers/owners: Mauritshuis, Rijksmuseum, Metropolitan, NGA.
• BM data uses crm:E22_Man-Made_Object. One of the current keepers is always the BM. The current owner may be missing (see BM Association Mapping Problems#Poor Acquisition), so we need to check both P52 and P50
• YCBA data uses crm:E22_Man-Made_Object, and the keeper/owner is YCBA.

The BM has two sameAs URIs

• http://collection.britishmuseum.org/id/the-british-museum
• http://collection.britishmuseum.org/id/person-institution/104636

So to avoid duplicate results, we define the dataset as a literal.
Then FC70_Thing is defined as something with a dataset.

Note: the Yale URI changed to a true ULAN URI, see Yale Mapping Problems#Getty URIs

Fundamental Relations

Sub-FRs

Here we define some auxiliary (sub) FRs that are used below.
We are careful to root all of them on FC70_Thing in order not to generate useless triples

• FRT_46_106_148 := (P46_is_composed_of | P106_is_composed_of | P148_has_component)+
  Rules

• FRT_46_106_148_128 := FRT_46_106_148 | P128_carries+
  Rules

• FRT_46_106_148_128_130 := FRT_46_106_148_128 | (P130_shows_features_of | P130i_features_are_also_found_on)+
  Rules

• FRT107i_member_of := P107i_is_current_or_former_member_of+
  Rules

• FRT9_10 := (P9_consists_of | P10_falls_within)+
  Rules

• FRX24i_30i := (FC70_Thing) (P24i_changed_ownership_through | P30i_custody_transferred_through)
  Rules

• FRX24i_25i_30i := (FC70_Thing) (FRX24i_30i | P25i_moved_by) / P9_consists_of*
  Rules

Thing-Place

Thing about Place- FR67_about_place

Thing depicts or refers to a place or feature located in place, or is similar in features or composed of or carries an information object that depicts or refers to a place

Fixes:

1. At beginning: does not allow paths of mixed properties (eg P130-P130i, P106-P148), or with P46,P106,P148 preceding P130,P130i
   • Resolved: we mix all these properties freely: any path of the indicated properties, in any order, of any length
2. At E73_Information_Object: does not allow P106_is_composed_of, P148_has_component which are legitimate for E73 (being a subclass of both E89_Propositional_Object and E90_Symbolic_Object)
   • Resolved: we add P128 into the mix.
     Did we mix it up too much? I think it's ok: not all allowed paths are correct, but all correct and relevant paths are allowed
3. At end: do not loop over the place hierarchy: About is neither covariant nor contravariant
   RS-1490
   • If a thing is about Knossos, it is not about every little village, house and room in Knossos
   • If a thing is about Rano Raraku, it is not about Easter Island, Polynesia, and Oceania

• FRX67_about := (FC70_Thing) FRT_46_106_148_128_130* (P62_depicts | P67_refers_to)
  This is the top branch but without a check for E53. It will be used in all "About" FRs
  Rules

• FRX67_about_feature_on_place := (FC70_Thing) FRT_46_106_148_128_130* / (P62_depicts | P67_refers_to) (E26_Physical_Feature) / P53
  This is the bottom branch
  Rules

• FR67_about_place := FRX67_about (E53_Place) | FRX67_about_feature_on_place
  Rules

Thing referred to at Place- WONTDO

Thing created in Place- FR92i_created_in

Thing (or part/inscription thereof) was created or modified/repaired at/in place (or a broader containing place)

The beginning is very similar to Thing created by Actor- FR92i_created_by, so we reuse from there

• FR92i_created_in := FRX92i_created / P7_took_place_at / P89_falls_within*
  Rules

Thing used at Place- WONTDO

No such in BM data

Thing located in Place- FR55_located_in

Thing has current or permanent location in Place (or a broader containing place)

• No need to loop over parts, since they are never at a different place

• FR55_located_in := (FC70_Thing) (P55_has_current_location | P54_has_current_permanent_location) / P89_falls_within*
  Rules

Thing found at Place- FR12_found_at

Thing was found (discovered, excavated) at Place

• We don't loop at the beginning since object parts don't have a different findspot from the main object
• The original definition also had "or acquired", but we don't need that

• FR12_found_at := (E70_Thing) P12i (EX_Discovery) / P7 / P89*
  Rules

Thing from Place- FR7_from_place

Thing has former, current or permanent location at place, or was created/found at place, or moved to/from place, or changed ownership/custody at place (or a broader containing place)

Corrections:

1. The original had "was created by someone born at place, or part of a group having residence at place". Although BM Person thesaurus provides birth place details, Dominic doesn't want this branch
2. We use the previously defined FRs "created in", "found at"
3. Added E10_Transfer_of_Custody in addition to E8_Acquisition
4. Loop P9_consists_of for E8_Acquisition
5. Don't loop at the beginning since there's no info about separate Move/Acquisition/Custody of a part
6. P26,P27 are subproperties of P7, so we don't need to use them

Implementation:

• FRX7_from_place := FRX24i_25i_30i / P7_took_place_at
  Rules

• FR7_from_place := FR92i_created_in | FR12_found_at |
  (FC70_Thing) (P53_has_former_or_current_location | P54_has_current_permanent_location | FRX7_from_place) / P89_falls_within*
  Rules

Thing-Thing- WONTDO

We don't have any info about top-level Thing-Thing relations in Rembrandt nor BM data.

• In Rembrandt there is part composition info, but we don't display other than top-level objects
• In one case "<painting> P130i_features_are_also_found_on <sketch>", but these relate to sub-objects, eg

So we won't do:

• Thing has met Thing
• Thing refers to or is about Thing
• Thing is referred to by Thing
• Thing from Thing
• Thing is part of Thing
• Thing was made from Thing
• Thing has part Thing
• Thing is similar or same with Thing

Thing-Actor

Thing has owner-keeper Actor- FR52_current_owner_keeper

Thing has current owner or keeper Actor

• The original definition of FR14_by is a mix (mess) of "created, measured, modified, acquired or used for activity performed by actor", but we decided to restrict it

Implementation:

Thing has former owner or keeper Actor- FR51_former_or_current_owner_keeper

Thing has former or current owner or keeper Actor, or ownership/custody was transferred from/to actor in Acquisition/Transfer of Custody event

Note: this subsumes Thing has owner-keeper Actor- FR52_current_owner_keeper

Implementation: FRX24i_30i goes to E8,E10. We don't need to check any type

Thing created by Actor- FR92i_created_by

Thing (or part/inscription thereof) was created or modified/repaired by Actor (or group it is member of)

Corrections:

• instead of a generic P92i_was_brought_into_existence_by, we want these specific paths:
  • produced by: P108i_was_produced_by
  • produced by subevent: P108i_was_produced_by/P9_consists_of
    We loop over the event hierarchy downwards since that's how BM data is laid out:

    <object/RFM1664> P108i_was_produced_by <object/RFM1664/production>.
    <object/RFM1664/production> P9_consists_of <object/RFM1664/production/1>.
    <object/RFM1664/production/1> P14_carried_out_by <person>.
    

  • modified (repaired) by: P31i_was_modified_by (subsumes P108i_was_produced_by)
  • part made by: P46_is_composed_of/P108i_was_produced_by
  • inscription by: P65_shows_visual_item/P94i_was_created_by (subsumed by P128_carries)
• in addition to P46_is_composed_of for physical, we add P106_is_composed_of and P148_has_component for conceptual

Implementation:

• FRX92i_created := (FC70_Thing) FRT_46_106_148_128* / (P31i_was_modified_by | P94i_was_created_by) / P9*
  Rules

• FR92i_created_by := FRX92i_created / P14_carried_out_by / P107i_is_current_or_former_member_of*
  Rules

Thing influenced-motivated by Actor- FR15_influenced_by

Thing's production was influenced/motivated by Actor (or group it is member of).

• Examples of Influenced include Manner/Style of, After, Close to, Connected with.
• Examples of Motivated include Eponym/Governor/Issuer/Ruler/Magistrate who authorised/patronised/ordered the production; Made for.

We usere the same beginning as Thing created by Actor- FR92i_created_by:

Implementation: P15_was_influenced_by subsumes P17_was_motivated_by.

Thing found by Actor- FR12_found_by

Thing was found (discovered, excavated) by Actor

Thing has met Actor- FR12_has_met

Thing (or part thereof) has met Actor in the same event, or Actor was involved in its acquisition or custody

Fixed Problems:

1. At beginning: we loop down the part hierarchy, for both physical and conceptual (P12 is applicable to any E77_Persistent_Item)
2. We loop down the event hierarchy (P9_consists_of) since that's how BM data is laid out
3. Curiously, CRM considers that a thing is not present at its E8_Acquisition or E10_Transfer_of_Custody: P24i_changed_ownership_through and P30i_custody_transferred_through are not subprops of P12i_was_present_at. Although physically possible, we have found that is surprising and confusing, so we add it.

Implementation:

• FR12X := (FC70_Thing) FRT_46_106_148* / P12i_was_present_at / P9_consists_of*
  Rules
• FR12_has_met := FR12X / P12_occurred_in_the_presence_of (E39_Actor) |
  FR51_former_or_current_owner_keeper
  Rules

Thing is referred to by Actor- WONTDO

A related example in RKD data is: <Gertruidenberg> (Place) P67i_is_referred_to_by <Bathing Susana> which is created by <Rembrandt>,
which would map to <Gertruidenberg> "is referred to by" <Rembrandt>, except that Place is not a Thing.

Thing refers to or is about Actor- FR67_about_actor

The original definition (FORTH TR-429 p45) loops over the actor hierarchy (P107_has_current_or_former_member), which we think is wrong:
if a thing is about the United Nations, is it also about every nation that's member of the UN?

• FR67_about_actor := FRX67_about (E39_Actor)
  Rules

Thing-Event

Thing refers to or is about Event- FR67_about_period

Thing depicts or refers to event/period, or carries information object that is about event, or bears similarity with a thing that is about event

Fixed Problems:

1. Allowed Period, which is a super-class of Event
2. At end: don't navigate the event hierarchy (aboutness is neither covariant, nor contravariant)

Implementation: similar to other "About" properties so we reuse FRX67_about.
We reuse a lot of properties from above, so we don't need to define any auxiliary sub-FRs here

• FR67_about_period := FR67_about (E4_Period)
  Rules

Thing is referred to at Event- WONTDO

Thing has met Event- FR12_was_present_at

Thing was present at Event (eg exhibition) or is from Period

Implementation

• FR12_was_present_at := (FC70_Thing) FRT_46_106_148_128* / P12i / (P9|P10)*
  Rules

Navigating the Event Hierarchy

RS-1832
"Thing present at Ancient Egypt" (thes:x107598) should find all:

• things produced in that culture/period, eg GAA42731
• things produced in any sub-period thereof, eg GAA86605 (which is from the 26th Dynasty)

The data is like this:

<GAA42731> P108i_was_produced_by <GAA42731/production>.
<GAA42731/production> P9_consists_of <GAA42731/production/2>.
<GAA42731/production/2> P10_falls_within thes:x107598.
thes:x107598 skos:broader thes:x112519.

The BM data has some inconsistencies:

1. As reported at FR Transitivity#From Period: the Period thesaurus uses only skos:broader but not P9_consists_of to make the hierarchy.
   We fixed this in FRs in Jun 2013 with the file FR-Transitivity.ttl
2. As reported at BM Association Mapping Problems#Production sub-event not connected in Jul 2013: there's no direct link between <GAA42731> and <GAA42731/production/2>.
   I don't believe any of the problems reported on that page are fixed by BM

To cater to these inconsistencies, the FRs loop by (P9,P10,skos:broader)* which means:
If present at an event, a thing is considered to also be present at:

• sub-events (P9)
• super-periods (P10)
• their super-periods (skos:broader)

But as you see, the hierarchy is navigated up and down, which violates principles of covariance.

If someone does the CRM property If a data provider uses P9_consists_of (instead of skos:broader) to connect Periods, the following false inference will result: GAA42731 was present at Ancient Egypt, therefore it was present at all sub-period thereof, eg 26th Dynasty

Navigating the Part Hierarchy

Representing Acquisition

An acquisition can be modeled as an event having all these classes:

• E8_Acquisition: thing changes ownership
• E10_Transfer_of_Custody: thing changes custody
• E80_Part_Removal: thing is removed from old collection
• E79_Part_Addition: thing is added to BM collection

The following entities are present at an acquisition:

• the thing itself: (E8, E10), E80, E79
• the seller: E8, E10
• the seller's collection: E80
• the buyer: E8, E10
• the buyer's collection: E79

BUG

The loop P46i_forms_part_of causes a serious problem if E79_Part_Addition is used. Assume Thing1 and Thing2 are part of the BM_collection, THEN:

Thing2(E22_Man-Made_Object) -- P46i_forms_part_of -> BM_Collection (E78_Collection). # given
Thing1_Acquisition(E79_Part_Addition) -- P110_augmented -> BM_Collection. # given
BM_Collection -- P12i_was_present_at -> Thing1_Acquisition. # P110i is sub-property of P12
Thing2 -- FR12_was_present_at -> Thing1_Acquisition. # by the FR definition

This causes all BM objects to be present at all Acquisition events of each other, which is wrong:

• If Thing2 was added to BM after Thing1, it's causally impossible for Thing2 to be present at the acquisition of Thing1
• If Thing2 was added to BM before Thing1, you could say that while sitting in BM, it quietly observed the addition of Thing1, but that is silly and not useful.

This also causes quadratic growth of the repository, and seemingly exponential growth of loading times.

How to Fix

Cannot be fixed easily using negation: "P46i_forms_part_of <thing> where <thing> is not E78_Collection":

• Class negation causes much higher inferencing complexity in OWL
• I'm sure there are other twisted cases, eg "each part of a building observed all modifications that added other parts to that building"

We had some discussions about following P46i:

• for some FRs it's appropriate to follow the other direction P46 ("contra-variant" not "co-variant" FRs)
• for some FRs it's appropriate to follow neither P46i, nor P46 (eg for Thing about Entity)

For this FR, we loop over P46_is_composed_of in order to account for:

• part made by: P46_is_composed_of/P108i_was_produced_by/P14_carried_out_by
• inscription made by: P128_carries/P94_has_created/P14_carried_out_by

Thing-Concept

Thing is made of Material- FR45_is_made_of

Thing (or part thereof) consists of material

Corrections:

• Original definition Includes P33_used_specific_technique/P68_foresees_use_of, but I think that is far-fetched: P33 should refer to an explicitly defined procedure, and if P68 then it stands to reason the material was actually P126_employed!
• I use the same beginning as Thing created by Actor- FR92i_created_by to also catch repairs (P31i_was_modified_by).
  (P94i_was_created_by is superfluous here, but doesn't hurt)

Implementation:

• FR45_is_made_of := (FC70_Thing) FRT_46_106_148_128* / P45_consists_of |
  FRX92i_created / P126_employed
  Rules

Thing used technique- FR32_used_technique

The production/modification of Thing (or part thereof) used general technique

• This is an extension defined by me
• Similarly to Thing is made of Material- FR45_is_made_of, it uses the same beginning as Thing created by Actor- FR92i_created_by.
  P94i_was_created_by may be useful here: an immaterial feature on the object (eg Inscription) may be made using a specific technique,
• (I think P32_used_general_technique is more useful than P33_used_specific_technique, see Thing is made of Material- FR45_is_made_of above)

Implementation:

• FR32_used_technique := FRX92i_created / P32_used_general_technique
  Rules

Thing is/has Type- FR2_has_type

Thing has Type (or has shape, is of kind, is about subject, etc)

• FRThing.docx calls this "has type" but I think "is/has/about" matches the general usage "is Weapon", "has shape Vertical Rectangle", etc

Fixes:

• added P67 (E55_Type), since some types are attached using P67_refers_to (or P129_is_about),
  eg these RKD extension properties: rso:P129_has_iconclass, rso:P129_has_keyword
• added P128_carries (E73_Information_Object) to move from physical to conceptual, eg
• added "P127_has_broader_term" to search by type hierarchy

Implementation:

• FRX2_has_type := (FC70_Thing) / FRT_46_106_148_128* / (P2_has_type | P67_refers_to (E55_Type))
  Rules

• FR2_has_type := FRX2_has_type / P127_has_broader_term*
  Rules

Notes:

• Martin also adds here FR45_is_made_of. This would be easy to add with this clause:

  but our search UI currently has a restriction that the many-to-many relation "FRs-thesauri" should split both FRs and thesauri into equivalence classes.

Thing identified by Identifier- FR1_identified_by

Thing (or part thereof) has Identifier (exact-match string).
Extension defined by me:

• FR1_identified_by := (FC70_Thing) FRT_46_106_148* / P1_is_identified_by / (P3_has_note | rdfs:label)
  Rules

Notes:

• TODO: it may be better to stop at P1 so the identifier type can also be examined
• we add rdfs:label since that's what BM uses for identifier values (not P3_has_note)
  RS-1408

• FRX_label := P3 | rdfs:label
  Using such intermediate relation is very stupid, since it will double the number of label triples & literals in the repo

Thing-Image

In order to make access to images for display easier, and FR Enhancements#Search by Image faster, we implement two FRs according to the definitions in Search Result Fields#Display Fields

• rso:FR_main_representation: main image (denoted ?Image)
  Rule
  Rule

• rso:FR138i_representation: all images (denoted ?Images)
  Rule
  Rule