- From: Thomas Lörtsch <tl@rat.io>
- Date: Thu, 26 Oct 2023 17:48:39 +0200
- To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
- Cc: public-rdf-star-wg@w3.org
> On 26. Oct 2023, at 17:39, Peter F. Patel-Schneider <pfpschneider@gmail.com> wrote:
>
> What is the content type of telco.trig?
The syntax used is a modified version of TriG and in my editor naming it to be of type TriG provides useful syntax coloring. But maybe I misunderstand your question? Pure text below.
> peter
>
>
> On 10/26/23 11:27, Thomas Lörtsch wrote:
>> what I just presented
>> (thanks everybody for letting me take 10 minutes instead of 5! :-)
>> thomas
>
# CAVEAT
# this is not legal TriG, but declaring it as such
# still can provide soem useful syntax highlighting
# also this may contain pugs
Nested Graphs
proposal
DESIGN CONSIDERATIONS
The charter is the law, but every law needs interpretation.
The charter asks for an annotation device that is easy to use.
Such device should provide :
- TOKENS
administration
qualification
- ASSERTED
otherwise the connection to the annotated statement is too brittle
- GRAPHS
grouping (even just for the sake of it) is an important KR pattern
and it is easier to represent singletons with a grouping device
than the other way round
- IDENTIFIERS
essential for tokens, otherwise one more triple (see RDF-star :occurrenceOf)
- REFERENTIAL TRANSPARENCY
mainstream
- NESTING
resilience to change
multiple dimensions
(instead of "but we use named graphs for X, so can't use it for anything else")
- THE 20 in 80/20
literals for types, referential opacity, un-asserted assertions etc
separation of concerns
# the basic syntax
# a nested graph, named by a blank node
[]{:Alice :buys :Car}
# a nested graph with a name
[:X]{:Alice :buys :Car}
# two nested graphs, named by different blank nodes
[]{:Alice :buys :Car}
[]{:Alice :buys :Car}
# a nested graph nested within another nested graph
# nested with a named graph
:NG_1 {
[]{
:Alice :buys :Car .
[]{:Alice :buys :Car}
[:Y]{:Alice :buys :Car}
}
}
# every triple in every nested graph is asserted and referentially transparent
# middle of the road RDF
# this
[:Y]{:Alice :buys :Car} :says :Denis
# is just syntactic sugar for this
[:Y]{:Alice :buys :Car}
:Y :says :Denis .
# some proposals have done this to achieve the same goal
:Alice :buys :Car # :Z
:Z :says :Denis .
# a simplistic application of a nested graph
# a bit like property graphs
[]{:Alice :buys :Car}
:age 20 ; # who is 20 years old ?
:color :black ; # who is black ?
:paymentMethod :Cash ; # seems clear
:purpose :JoyRiding ; # dito
:model :Coupe ; # dito
:source :Denis . # dito ... or did Denis sell the car
# targeting fragments, verbosely
[:X]{:Alice :buys :Car} .
:X seg:subject [
:age 20
]
:X seg:predicate [
:paymentMethod :Cash ;
:purpose :JoyRiding # ambivalence, could also be object property
]
:X seg:object [
:color :black ;
:model :Coupe
]
:X seg:triple [
ex:void ex:void # forEach, not needed here
]
:X seg:graph [
:source :Denis
]
# a mapping to RDF a la singleton properties
:Alice :buys_1 :Car .
:buys_1
rdfs:subPropertyOf :buys ;
:paymentMethod :Cash ;
:purpose :JoyRiding ;
:nestedIn :X ;
rdfs:domain [
:age 20
];
rdfs:range [
:color :black ;
:model :Coupe
];
rdfx:triple [
:source :Denis
]
.
# two other mappings
# - with rdf:value and lots of blank nodes, and with named graphs -
# are provided in the long text
# a compact version of the nested graph
[:X]{
:Alice :buys :Car .
:X?s :age 20 .
:X?p :paymentMethod :Cash ;
:purpose :JoyRiding .
:X?o :color :black ;
:model :Coupe .
# :X?g :source :Denis
} :source :Denis . # doesn't provide an explicit ?g fragment identifier
# the same as RDF-star
:Alice_1 :buys_1 :Car_1 .
:Alice_1 rdf:type :Alice ;
:age 20 .
<< :Alice_1 :buys :Car_1 >> :source Denis .
<< :Alice_1 rdf:type :Alice >> :source Denis .
<< :Alice_1 :age 20 >> :source Denis .
:buys_1 rdfs:subPropertyOf :buys ;
:paymentMethod :Cash ;
:purpose :JoyRiding .
<< :buys_1 rdfs:subPropertyOf :buys >> :source Denis .
<< :buys_1 :paymentMethod :Cash >> :source Denis .
<< :buys_1 :purpose :JoyRiding >> :source Denis .
:Car_1 rdf:type :Car ;
:color :Black ;
:model :Coupe .
<< :Car_1 rdf:type :Car >> :source Denis .
<< :Car_1 :color :Black >> :source Denis .
<< :Car_1 :model :Coupe >> :source Denis .
# imagine what happens with a second level of nesting
# or even TEP
# embedded in Named Graphs as we know them
:NG_1 :source :Laptop ; # application specific graph annotations
:status :Unredacted ;
:visibility :Private .
:NG_1 {
[:Z]{
[:Y]{
[:X]{
:Alice :buys :Car .
:X?s :age 20 .
:X?p :paymentMethod :Cash ;
:purpose :JoyRiding .
:X?o :color :black ;
:model :Coupe .
} :source :Denis .
}
} :FirstCarEvent ;
:source :GreenDiary ; # imagine 2nd level nesting with RDF-star =:-|
:date :10_12_08 .
}
# add another level of nesting for different accounts of Alice buying her first car
# eg her parents helping fund it
# the insurance company having yet a dfifferent view
# a second AliceBuysCar triple
[:Y]{
[:X]{
:Alice :buys :Car .
:X?s :age 20 .
:X?p :paymentMethod :Cash ;
:purpose :JoyRiding .
:X?o :color :black ;
:model :Coupe .
} :source :Denis .
[:W]{
[:V]{
:Alice :buys :Car .
:V?s :age 28 .
} :source :Eve .
} :todo :AddDetail . # add detail
} # then remove this level of nesting
# without changing the data topology
# literals as un-asserted opaque types
[:Y]{
[:X]{
:Alice :buys :Car .
:X?s :age 20 .
:X?p :paymentMethod :Cash ;
:purpose :JoyRiding .
:X?o :color :black ;
:model :Coupe .
} :source :Denis ;
:asLiteral "[:X]{:Alice :buys :Car
:X?s :age 20 .
:X?p :paymentMethod :Cash ;
:purpose :JoyRiding .
:X?o :color :black ;
:model :Coupe ."^^rdfx:graph .
# literals as un-asserted transparent types
# (what RDF standard reifiaction is popularily misused to represent)
:Bob :says {" :Moon :madeOf :Cheese . "}
# { ... } indicate transparency
# " ... " indicate un-assertedness
:Bob :says [ seg:transcludesCitation ":Moon :madeOf :Cheese"^^rdfx:graph ]
# resilience to updates
[:Y]{
:Alice :buys :House . # <--- !
[:X]{
:Alice :buys :Car .
:X?s :age 20 .
:X?p :paymentMethod :Cash ;
:purpose :JoyRiding .
:X?o :color :black ;
:model :Coupe ;
:maker :Pininfarina . # <--- !!
}
} :source :Denis .
# --->
[:Y]{
[:W]{
:Alice :buys :House .
:W?s :age :40 . # <--- !!!
}
[:X]{
:Alice :buys :Car .
:X?s :age 20 .
:X?p :paymentMethod :Cash ;
:purpose :JoyRiding .
:X?o :color :black ;
:model :Coupe ;
:maker :Pininfarina .
} :source :Denis .
# DnS shortcut relations
[:T]{
:Alice :travelsTo :ISWC23 .
:T?p rdfs:seeAlso :U , :P.
}
[:U]{
:Schedule :startsAt :Hamburg ;
:byMeans :Plane ;
:date "05.11.2023" ;
:gate ...
:Purpose :see :P .
} a :Travel .
[:P]{
:Purpose :present :Paper ;
:topic :Metavisualization ;
...
}
Received on Thursday, 26 October 2023 15:48:49 UTC