# ============================================================================== # Delfour — Ruben Verborgh's "Inside the Insight Economy" case. # See https://ruben.verborgh.org/blog/2025/08/12/inside-the-insight-economy/ # # This example shows how a person can share a useful shopping hint without # exposing sensitive health details. A phone turns a private condition into a # neutral, limited insight such as “prefer lower-sugar products”, attaches clear # usage rules and an expiry time, and sends it to a store scanner. The scanner # may use that insight to suggest a better product, but not for unrelated # purposes such as marketing. # ============================================================================== @prefix : . @prefix arc: . @prefix ins: . @prefix odrl: . @prefix log: . @prefix math: . @prefix string: . @prefix crypto: . @prefix xsd: . # ----- # Facts # ----- :case a arc:Case ; :caseName "delfour" ; arc:question "Is the Delfour self-scanner allowed to use a neutral shopping insight for shopping assistance, and if so what lower-sugar alternative should it suggest?" ; :expectedFilesWritten 6 ; :requestPurpose "shopping_assist" ; :requestAction odrl:use ; :phoneCreatedAt "2025-10-05T20:33:48.907163+00:00"^^xsd:dateTime ; :phoneExpiresAt "2025-10-05T22:33:48.907185+00:00"^^xsd:dateTime ; :scannerAuthAt "2025-10-05T20:35:48.907163+00:00"^^xsd:dateTime ; :scannerDutyAt "2025-10-05T20:37:48.907163+00:00"^^xsd:dateTime ; :filesWritten 6 ; :auditEntries 1 . :catalog a :Catalog . :prod_BIS_001 a :Product ; :productId "prod:BIS_001" ; :productName "Classic Tea Biscuits" ; :sugarTenths 120 ; :sugarPerServing 12.0 . :prod_BIS_101 a :Product ; :productId "prod:BIS_101" ; :productName "Low-Sugar Tea Biscuits" ; :sugarTenths 30 ; :sugarPerServing 3.0 . :prod_CHOC_050 a :Product ; :productId "prod:CHOC_050" ; :productName "Milk Chocolate Bar" ; :sugarTenths 150 ; :sugarPerServing 15.0 . :prod_CHOC_150 a :Product ; :productId "prod:CHOC_150" ; :productName "85% Dark Chocolate" ; :sugarTenths 60 ; :sugarPerServing 6.0 . :householdProfile :condition "Diabetes" . :scan :scannedProduct :prod_BIS_001 . a ins:Insight ; :metric "sugar_g_per_serving" ; :thresholdTenths 100 ; :thresholdDisplay "10.0" ; :thresholdG 10.0 ; :suggestionPolicy "lower_metric_first_higher_price_ok" ; :scopeDevice "self-scanner" ; :scopeEvent "pick_up_scanner" ; :retailer "Delfour" ; :createdAt "2025-10-05T20:33:48.907163+00:00"^^xsd:dateTime ; :expiresAt "2025-10-05T22:33:48.907185+00:00"^^xsd:dateTime ; :serializedLowercase "{\"createdat\":\"2025-10-05t20:33:48.907163+00:00\",\"expiresat\":\"2025-10-05t22:33:48.907185+00:00\",\"id\":\"https://example.org/insight/delfour\",\"metric\":\"sugar_g_per_serving\",\"retailer\":\"delfour\",\"scopedevice\":\"self-scanner\",\"scopeevent\":\"pick_up_scanner\",\"suggestionpolicy\":\"lower_metric_first_higher_price_ok\",\"threshold\":10.0,\"type\":\"ins:insight\"}" . :policy a odrl:Policy ; :profile "Delfour-Insight-Policy" ; odrl:permission [ odrl:action odrl:use ; odrl:target ; odrl:constraint [ odrl:leftOperand odrl:purpose ; odrl:operator odrl:eq ; odrl:rightOperand "shopping_assist" ] ] ; odrl:prohibition [ odrl:action odrl:distribute ; odrl:target ; odrl:constraint [ odrl:leftOperand odrl:purpose ; odrl:operator odrl:eq ; odrl:rightOperand "marketing" ] ] ; odrl:duty [ odrl:action odrl:delete ; odrl:constraint [ odrl:leftOperand odrl:dateTime ; odrl:operator odrl:eq ; odrl:rightOperand "2025-10-05T22:33:48.907185+00:00"^^xsd:dateTime ] ] . :envelope :insight ; :policy :policy ; :canonicalJson "{\"insight\":{\"createdAt\":\"2025-10-05T20:33:48.907163+00:00\",\"expiresAt\":\"2025-10-05T22:33:48.907185+00:00\",\"id\":\"https://example.org/insight/delfour\",\"metric\":\"sugar_g_per_serving\",\"retailer\":\"Delfour\",\"scopeDevice\":\"self-scanner\",\"scopeEvent\":\"pick_up_scanner\",\"suggestionPolicy\":\"lower_metric_first_higher_price_ok\",\"threshold\":10.0,\"type\":\"ins:Insight\"},\"policy\":{\"duty\":{\"action\":\"odrl:delete\",\"constraint\":{\"leftOperand\":\"odrl:dateTime\",\"operator\":\"odrl:eq\",\"rightOperand\":\"2025-10-05T22:33:48.907185+00:00\"}},\"permission\":{\"action\":\"odrl:use\",\"constraint\":{\"leftOperand\":\"odrl:purpose\",\"operator\":\"odrl:eq\",\"rightOperand\":\"shopping_assist\"},\"target\":\"https://example.org/insight/delfour\"},\"profile\":\"Delfour-Insight-Policy\",\"prohibition\":{\"action\":\"odrl:distribute\",\"constraint\":{\"leftOperand\":\"odrl:purpose\",\"operator\":\"odrl:eq\",\"rightOperand\":\"marketing\"},\"target\":\"https://example.org/insight/delfour\"},\"type\":\"odrl:Policy\"}}" . :signature :alg "HMAC-SHA256" ; :keyid "demo-shared-secret" ; :created "2025-10-05T20:33:48.907163+00:00"^^xsd:dateTime ; :payloadHashSHA256 "34ad35638dfd7c67d031eeca8abb235ec24280740f863f3f31cd9d7b6517f098" ; :signatureHMAC "b21d0072d90112a9f820aced0286889f4b6ef92b145e6fdef1011f3bfa4608c2" ; :hmacVerificationMode :trustedPrecomputedInput . :reasonText :value "Household requires low-sugar guidance (diabetes in POD). A neutral Insight is scoped to device 'self-scanner', event 'pick_up_scanner', retailer 'Delfour', and expires soon; the policy confines use to shopping assistance.\n" . # ----- # Logic # ----- # desensitize(&["Diabetes"]) -> true { :householdProfile :condition "Diabetes" . } => { :case :needsLowSugar true . } . # derive_insight(...) { :case :needsLowSugar true . } => { :derivedFromNeed "low_sugar" . } . # payload_hash_matches { :envelope :canonicalJson ?json . ?json crypto:sha256 ?digest . :signature :payloadHashSHA256 ?digest . } => { :check :payloadHashMatches true . } . # signature_verified { :signature :hmacVerificationMode :trustedPrecomputedInput . } => { :check :signatureVerifies true . } . # minimization_no_sensitive_terms { :serializedLowercase ?s . ?s string:notMatches "diabetes|medical" . } => { :check :minimizationStripsSensitiveTerms true . } . # scope_complete { :scopeDevice ?device ; :scopeEvent ?event ; :expiresAt ?expiry . } => { :check :scopeComplete true . } . # authorization_allowed { :policy odrl:permission [ odrl:action odrl:use ; odrl:target ; odrl:constraint [ odrl:leftOperand odrl:purpose ; odrl:operator odrl:eq ; odrl:rightOperand "shopping_assist" ] ] . :case :scannerAuthAt ?authAt . :expiresAt ?expiresAt . ?authAt math:notGreaterThan ?expiresAt . } => { :decision :at "2025-10-05T20:35:48.907163+00:00"^^xsd:dateTime ; :outcome "Allowed" ; :target . :check :authorizationAllowed true . } . # banner if scanned product meets/exceeds threshold { :decision :outcome "Allowed" . :scan :scannedProduct ?product . ?product :sugarPerServing ?sugar . :thresholdG ?threshold . ?sugar math:notLessThan ?threshold . } => { :banner :headline "Track sugar per serving while you scan" ; :note "High sugar" . :check :bannerFlagsHighSugar true . } . # choose the lower-sugar alternative with the smallest sugar score { :scan :scannedProduct ?scanned . ?scanned :sugarTenths ?scannedSugar . ?candidate a :Product ; :sugarTenths ?candidateSugar . ?scannedSugar math:greaterThan ?candidateSugar . 1 log:notIncludes { ?other a :Product ; :sugarTenths ?otherSugar . ?scannedSugar math:greaterThan ?otherSugar . ?otherSugar math:lessThan ?candidateSugar . } . } => { :case :suggestedAlternative ?candidate . } . { :banner :note "High sugar" . :case :suggestedAlternative ?alt . ?alt :productName ?altName . } => { :banner :suggestedAlternative ?altName . } . { :scan :scannedProduct ?scanned . ?scanned :sugarTenths ?scannedSugar . :case :suggestedAlternative ?alt . ?alt :sugarTenths ?altSugar . ?scannedSugar math:greaterThan ?altSugar . } => { :check :alternativeIsLowerSugar true . } . # duty_timing_consistent { :case :scannerDutyAt ?dutyAt . :expiresAt ?expiresAt . ?dutyAt math:notGreaterThan ?expiresAt . } => { :check :dutyTimingConsistent true . } . # marketing_prohibited { :policy odrl:prohibition [ odrl:action odrl:distribute ; odrl:constraint [ odrl:rightOperand "marketing" ] ] . } => { :check :marketingProhibited true . } . # file count check mirrors EXPECTED_FILES_WRITTEN { :case :filesWritten 6 . } => { :check :filesWrittenExpected true . } . { :check :signatureVerifies true ; :payloadHashMatches true ; :minimizationStripsSensitiveTerms true ; :scopeComplete true ; :authorizationAllowed true ; :bannerFlagsHighSugar true ; :alternativeIsLowerSugar true ; :dutyTimingConsistent true ; :marketingProhibited true ; :filesWrittenExpected true . } => { :result :allChecksPass true . } . # ------------------------------------- # Hard checks (Eyeling inference fuses) # ------------------------------------- { :case :filesWritten ?n . ?n math:notEqualTo 6 . } => false . { :case :scannerAuthAt ?authAt . :expiresAt ?expiresAt . ?authAt math:greaterThan ?expiresAt . } => false . { :scan :scannedProduct ?scanned . ?scanned :sugarTenths ?scannedSugar . :case :suggestedAlternative ?alt . ?alt :sugarTenths ?altSugar . ?altSugar math:notLessThan ?scannedSugar . } => false . { :policy odrl:prohibition [ odrl:action ?action ] . ?action log:notEqualTo odrl:distribute . } => false . { :envelope :canonicalJson ?json . ?json crypto:sha256 ?actual . :signature :payloadHashSHA256 ?expected . ?actual log:notEqualTo ?expected . } => false . # -------------------------------------- # ARC rendering through log:outputString # -------------------------------------- :out01 log:outputString "=== Answer ===\n" . :out02 log:outputString "The scanner is allowed to use a neutral shopping insight and recommends Low-Sugar Tea Biscuits instead of Classic Tea Biscuits.\n" . :out03 log:outputString "case : delfour\n" . :out04 log:outputString "decision : Allowed\n" . :out05 log:outputString "scanned product : Classic Tea Biscuits\n" . { :case :suggestedAlternative ?alt . ?alt :productName ?altName . ("suggested alternative: %s\n" ?altName) string:format ?line . } => { :out06 log:outputString ?line . } . :out07 log:outputString "\n=== Reason Why ===\n" . :out08 log:outputString "The phone desensitizes a diabetes-related household condition into a scoped low-sugar need, wraps it in an expiring Insight + Policy envelope, signs it, and the scanner consumes that envelope for shopping assistance.\n" . :out09 log:outputString "metric : sugar_g_per_serving\n" . { :thresholdDisplay ?threshold . ("threshold : %s\n" ?threshold) string:format ?line . } => { :out10 log:outputString ?line . } . :out11 log:outputString "scope : self-scanner @ pick_up_scanner\n" . :out12 log:outputString "retailer : Delfour\n" . { :signature :alg ?alg . ("signature alg : %s\n" ?alg) string:format ?line . } => { :out13 log:outputString ?line . } . { :banner :headline ?headline . ("banner headline : %s\n" ?headline) string:format ?line . } => { :out14 log:outputString ?line . } . :out15 log:outputString "expires at : 2025-10-05T22:33:48.907185+00:00\n" . { :reasonText :value ?reason . ("reason.txt : %s" ?reason) string:format ?line . } => { :out16 log:outputString ?line . } . { :case :auditEntries ?n . ("audit entries : %s\n" ?n) string:format ?line . } => { :out17 log:outputString ?line . } . { :case :filesWritten ?n . ("bus files written : %s\n" ?n) string:format ?line . } => { :out18 log:outputString ?line . } . :out19 log:outputString "\n=== Check ===\n" . { :check :signatureVerifies true . } => { :out20 log:outputString "signature verifies : yes\n" . } . { :check :payloadHashMatches true . } => { :out21 log:outputString "payload hash matches : yes\n" . } . { :check :minimizationStripsSensitiveTerms true . } => { :out22 log:outputString "minimization strips sensitive terms: yes\n" . } . { :check :scopeComplete true . } => { :out23 log:outputString "scope complete : yes\n" . } . { :check :authorizationAllowed true . } => { :out24 log:outputString "authorization allowed : yes\n" . } . { :check :bannerFlagsHighSugar true . } => { :out25 log:outputString "high-sugar banner : yes\n" . } . { :check :alternativeIsLowerSugar true . } => { :out26 log:outputString "alternative lowers sugar : yes\n" . } . { :check :dutyTimingConsistent true . } => { :out27 log:outputString "duty timing consistent : yes\n" . } . { :check :marketingProhibited true . } => { :out28 log:outputString "marketing prohibited : yes\n" . } .