notation.n3

@prefix : <urn:example:> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix math: <http://www.w3.org/2000/10/swap/math#> .

# Paths
#  :book1 :metadata [
#        :author [
#           :lastName "Austen"
#           :fistName "Jane" .
#        ]
#  ]
:book1!:metadata!:author 
        :lastName "Austen" ;
        :firstName "Jane" .

# NOTE: This is not equal to:
#
:book2!:metadata!:author :lastName "Austen" .  # 1
:book2!:metadata!:author :firstName "Jane" .   # 2
#
# Why? #1 and #2 are different paths

# :book3 :metadata [
#      :author _:anAuthor
# ] .
# _:somebody :father _:anAuthor ;
#            :lastName "Boll" .
:book3!:metadata!:author^:father :lastName "Boll" .

# Paths can also be used in calculations
{
    # (2 + 2) * 3
    ( (2 2)!math:sum 3 ) math:product ?X .
}
=>
{
    :result :is ?X .
} .

# Collections
:book4 :readBy ( :Jos :Pat :Ruben ) .
(:book1 :book2) :readBy ( :Jos :Pat :Ruben ).
(:book1 :book3) (:readBy :likedBy) (:Jos :Ruben).

# The equal sign is used to express an owl:sameAs identity.
# This means the subject and object IRI refer to the same
# thing. This does NOT mean that the subject and object IRI 
# are equal. This also does NOT mean that any inferences
# you make about the subject are also valid for the object.
#
# This will not work:
#
#      :Alice :knows :Bob .
#      :Alice = <http://alice.pods.me/profile/card#me> .
#      {
#         ?A :knows ?B .
#      }
#      => 
#      {
#         ?B :knows ?A ,
#      } .  
#
# and expecting as answer:
#
#      <http://alice.pods.me/profile/card#me> :knows :Bob.
:Alice :knows :Bob .
:Alice = <http://alice.pods.me/profile/card#me> .

{
    ?A :knows ?B .
}
=>
{
    ?B :knows ?A .
} .

# Test
{
    :book1 :metadata [
        :author [
            :lastName "Austen" ;
            :firstName "Jane" 
        ]
    ] .

    :book2 :metadata [
        :author [
            :lastName "Austen" ;
        ]
    ] .

    :book2 :metadata [
        :author [
            :firstName "Jane" ;
        ]
    ] .

    :book3 :metadata [
        :author _:x
    ] .
    _:y :father _:x ;
        :lastName "Boll" .

    :book4 :readBy (:Jos :Pat :Ruben) .
    (:book1 :book2) :readBy (:Jos :Pat :Ruben).
    (:book1 :book3) (:readBy :likedBy) (:Jos :Ruben).

    :result :is 12 .
}
=>
{
    :test :is true .
} .