PROV-DM Part 3: PROV-N: The Provenance Notation

Table of Contents

• 1. Introduction
  • 1.1 Structure of this Document
  • 1.2 PROV-DM Namespace
  • 1.3 Conventions
• 2. Grammar Notation
• 3. PROV-DM Core
  • 3.1 Element
    • 3.1.1 Entity
    • 3.1.2 Activity
    • 3.1.3 Agent
    • 3.1.4 Note
  • 3.2 Relation
    • 3.2.1 Generation
    • 3.2.2 Usage
    • 3.2.3 Activity Association
    • 3.2.4 Activity Start and End
    • 3.2.5 Responsibility Chain
    • 3.2.6 Derivation
    • 3.2.7 Alternate and Specialization
    • 3.2.8 Annotation
  • 3.3 Further Expressions
    • 3.3.1 Namespace Declaration
    • 3.3.2 Identifier
    • 3.3.3 Attribute
    • 3.3.4 Literal
      • 3.3.4.1 Reserved Type Values
      • 3.3.4.2 Time Values
• 4. Common Relations
• 5. Expression Container
• 6. Account
• A. References
  • A.1 Normative references
  • A.2 Informative references

1. Introduction

Provenance is defined as a record that describes the people, institutions, entities, and activities, involved in producing, influencing, or delivering a piece of data or a thing in the world. Two companion specifications respectively define PROV-DM, a data model for provenance, allowing such descriptions to be expressed [PROV-DM] and a set of constraints that provenance descriptions are expectively to satisfy [PROV-DM-CONSTRAINTS].

In this context, PROV-N was introduced as a notation to write instances of the data model, as close to its abstract syntax as possible. PROV-N is primarily aimed at human consumption. PROV-N allows serializations of PROV-DM instances to be written in a technology independent manner. So far, PROV-N has been used in the following ways:

• PROV-N is used to provide technology independent illustrations in [PROV-DM] and in the definition of PROV-DM constraints [PROV-DM-CONSTRAINTS];
• PROV-N is instrumental in defining the mapping mapping of PROV-DM to concrete syntaxes. Mappings translate each PROV-N expression to RDF [PROV-RDF] and to XML [PROV-XML];
• PROV-N is the basis for a formal semantics, in which each PROV-N expression is provided with an interpretation [PROV-SEM].

PROV-N was designed to be as close as possible to PROV-DM without the syntactic bias and modelling constraints that concrete technologies bring with them, e.g., XML's choice between attribute and element, RDF's reliance on triples, or JSON's usage of dictionaries.

The purpose of this document is solely to define the syntax of PROV-N. For each construct of PROV-DM, a corresponding PROV-N expression is introduced, by way of a production in the PROV-N grammar presented in this document.

This specification is one of several specifications, referred to as the PROV family of specifications, defining the various aspects that are necessary to achieve the vision of inter-operable exchange of provenance:

• A data model for provenance, which is presented in three documents:
  • PROV-DM (part I): the provenance data model itself, expressed in natural language [PROV-DM];
  • PROV-DM-CONSTRAINTS (part II): constraints underpinning the data model [PROV-DM-CONSTRAINTS];
  • PROV-N (part III): a notation to express instances of that data model for human consumption (this document);
• PROV-O: a normative serialization of PROV-DM in RDF [PROV-O], specified by means of a mapping to the OWL2 Web Ontology Language [OWL2-SYNTAX];
• PROV-AQ: the mechanisms for accessing and querying provenance [PROV-AQ];
• PROV-PRIMER: a primer for the PROV approach [PROV-PRIMER];
• PROV-SEM: semantics of the PROV-DM data model [PROV-SEM];

2. Grammar Notation

This specification includes a grammar for PROV-N expressed using the Extended Backus-Naur Form (EBNF) notation.

3. PROV-DM Core

Instances of the PROV-DM data model are expressed in PROV-N by a text conformant with the toplevel production expression of the grammar. These expressions are grouped in two categories: elementExpression (see section Element) and relationExpression (see section Relation).

entity(tr:WD-prov-dm-20111215)
entity(tr:WD-prov-dm-20111215, [ prov:type="document" ])
entity(tr:WD-prov-dm-20111215, [ prov:type="document", ex:version=2 ])

activity(ex:edit1,,)
activity(ex:edit1,,,[prov:type="edit"])
activity(ex:a0, 2011-11-16T16:00:00,,[prov:type="createFile"])
activity(ex:a0, 2011-11-16T16:00:00, 2011-11-16T16:00:01, [prov:type="createFile"])

agent(ag4)
agent(ag4, [ prov:type="prov:Human" %% xsd:QName, ex:name="David" ])

note(ann1,[ex:color="blue", ex:screenX=20, ex:screenY=30])

wasGeneratedBy(tr:WD-prov-dm-20111215, ex:edit1)
wasGeneratedBy(tr:WD-prov-dm-20111215, ex:edit1, 2011-11-16T16:00:00)
wasGeneratedBy(ex:g1, tr:WD-prov-dm-20111215, ex:edit1)
wasGeneratedBy(e2, a1, [ex:fct="save"])     

used(ex:pub2, ar3:0111)
used(ex:pub2, ar3:0111, 2011-11-16T16:00:00)
used(ex:u1, ex:pub2, ar3:0111)
used(a1,e1,[ex:fct="load"])

wasAssociatedWith(ex:pub2, w3:Consortium)
wasAssociatedWith(ex:pub2, w3:Consortium  @ pr:rec-advance)
wasAssociatedWith(ex:pub2, w3:Consortium  @ pr:rec-advance, [prov:role="funder"])

actedOnBehalfOf(ag1,ag2)
actedOnBehalfOf(ag1,ag2,a)
actedOnBehalfOf(ag1,ag2,[prov:type="delegation"])
actedOnBehalfOf(ag2,ag3,a,[prov:type="contract"])

wasDerivedFrom(tr:WD-prov-dm-20111215, tr:WD-prov-dm-20111018)
wasDerivedFrom(e2, e1, a, g2, u1)

alternateOf(tr:WD-prov-dm-20111215,ex:alternate-20111215)

specializationOf(tr:WD-prov-dm-20111215,tr:prov-dm)

hasAnnotation(tr:WD-prov-dm-20111215,ex2:n1)

4. Common Relations

5. Expression Container

An expression container is a house-keeping construct of PROV-N capable of packaging up PROV-N expressions and namespace declarations. An expression container forms a self-contained package of provenance descriptions for the purpose of exchanging them. An expression container may be used to package up PROV-N expressions in response to a request for the provenance of something ([PROV-AQ]).

Given its status of house keeping construct for the purpose of exchanging provenance expressions, an expression container is not defined as a PROV-N expression (production expression).

An expression container, written container decls exprs endContainer in PROV-N, contains:

• namespaceDeclarations: a set decls of namespace declarations, declaring namespaces and associated prefixes, which can be used in attributes and identifiers occurring inside exprs;
• expressions: a non-empty set of expressions exprs.

An expression container's text matches the expressionContainer production.

container

  prefix ex: http://example.org/,

  entity(e2, [ prov:type="File", ex:path="/shared/crime.txt", ex:creator="Alice", 
             ex:content="There was a lot of crime in London last month."])
  activity(a1, 2011-11-16T16:05:00,,[prov:type="edit"])
  wasGeneratedBy(e2, a1, [ex:fct="save"])     
  wasAssociatedWith(a1, ag2, [prov:role="author"])
  agent(ag2, [ prov:type="prov:Person" %% xsd:QName, ex:name="Bob" ])

endContainer

6. Account

PROV-DM has introduced a notion of account by which a set of provenance descriptions can be bundled up and named. PROV-DM assumes the existence of mechanisms to implement accounts, but such mechanisms remain outside its scope. It is suggested that specific serializations may offer solutions to name bundles of descriptions.

Given that the primary motivation for PROV-N is to provide a notation aimed at human consumption, it is therefore appropriate to introduce a notation for accounts, which would include an account name and a bundle of expressions.

An account, written account(id, exprs) in PROV-N, contains:

• id: an identifier id that identifies this account;
• expressions: a set exprs of expressions;

In PROV-N, an account's text matches the accountExpression production of the grammar.

It is also useful to package up one or more account expressions in an expression container, for interchange purpose. Hence, expressionContainer is revised as follows.

container
  prefix ex: http://example.org/,

  account(ex:acc1,...)
  account(ex:acc2,...)
endContainer

container
  prefix ex: http://example.org/,
  ...

  account(ex:acc1,
      entity(tr:WD-prov-dm-20111018, [ prov:type="pr:RecsWD" %% xsd:QName ])
      entity(tr:WD-prov-dm-20111215, [ prov:type="pr:RecsWD" %% xsd:QName ])
      ...
      wasAssociatedWith(ex:pub2, w3:Consortium  @ pr:rec-advance))

  account(ex:acc2,
      entity(ex:acc1, [prov:type="prov:AccountEntity" %% xsd:QName ])
      wasAttributedTo(ex1:acc1,w3:Consortium))

endContainer