OWL 2 Web Ontology Language:
Manchester Syntax

1 Introduction

2 The Grammar

The Manchester syntax of OWL 2 is defined using a standard BNF notation, which is summarized in the table below.

Because comma-separated lists occur in very many places in the syntax, to save space the grammar has three meta-productions, one for non-empty lists, one for lists of minimum length two, and one for non-empty lists with annotations in them.

<NT>List ::= <NT> { , <NT> } <NT>2List ::= <NT> , <NT>List <NT>AnnotatedList ::= [annotations] <NT> { , [annotations] <NT> }

2.1 IRIs, Integers, Literals, and Entities

2.2 Ontologies and Annotations

annotations ::= 'Annotations:' annotationAnnotatedList annotation ::= annotationPropertyIRI annotationTarget annotationTarget ::= nodeID | IRI | literal ontologyDocument ::= { namespace } ontology namespace ::= 'Namespace:' [ prefix ] full-IRI ontology ::= 'Ontology:' [ ontologyIRI [ versionIRI ] ] { import } { annotations } { frame } ontologyIRI ::= IRI versionIRI ::= IRI import ::= 'Import:' IRI frame ::= classFrame | objectPropertyFrame | dataPropertyFrame | annotationPropertyFrame | individualFrame | misc

The 'rdf', 'rdfs', 'owl', and 'xsd' prefixes are pre-defined as follows and cannot be changed.

2.3 Property and Datatype Expressions

objectPropertyExpression ::= objectPropertyIRI | inverseObjectProperty inverseObjectProperty ::= 'inverse' objectPropertyIRI dataPropertyExpression ::= dataPropertyIRI dataRange ::= dataConjunction 'or' dataConjunction { 'or' dataConjunction } | dataConjunction dataConjunction ::= dataPrimary 'and' dataPrimary { 'and' dataPrimary } | dataPrimary dataPrimary ::= [ 'not' ] dataAtomic dataAtomic ::= Datatype | '{' literal { ',' literal } '}' | datatypeRestriction | '(' dataRange ')' datatypeRestriction ::= Datatype '[' facet restrictionValue { ',' facet restrictionValue } ']' facet ::= 'length' | 'minLength' | 'maxLength' | 'pattern' | 'langPattern' | '<=' | '<' | '>=' | '>' restrictionValue ::= literal

2.4 Descriptions

description ::= conjunction 'or' conjunction { 'or' conjunction } | conjunction conjunction ::= classIRI 'that' [ 'not' ] restriction { 'and' [ 'not' ] restriction } | primary 'and' primary { 'and' primary } | primary primary ::= [ 'not' ] ( restriction | atomic ) restriction ::= objectPropertyExpression 'some' primary | objectPropertyExpression 'only' primary | objectPropertyExpression 'value' individual | objectPropertyExpression 'Self' | objectPropertyExpression 'min' nonNegativeInteger [ primary ] | objectPropertyExpression 'max' nonNegativeInteger [ primary ] | objectPropertyExpression 'exactly' nonNegativeInteger [ primary ] | dataPropertyExpression 'some' dataPrimary | dataPropertyExpression 'only' dataPrimary | dataPropertyExpression 'value' literal | dataPropertyExpression 'min' nonNegativeInteger [ dataPrimary ] | dataPropertyExpression 'max' nonNegativeInteger [ dataPrimary ] | dataPropertyExpression 'exactly' nonNegativeInteger [ dataPrimary ] atomic ::= classIRI | '{' individual { ',' individual } '}' | '(' description ')'

2.5 Frames and Miscellaneous

classFrame ::= 'Class:' classIRI { 'Annotations:' annotationAnnotatedList | 'SubClassOf:' descriptionAnnotatedList | 'EquivalentTo:' descriptionAnnotatedList | 'DisjointWith:' descriptionAnnotatedList | 'DisjointUnionOf:' annotations description2List } objectPropertyFrame ::= 'ObjectProperty:' objectPropertyIRI { 'Annotations:' annotationAnnotatedList | 'Domain:' descriptionAnnotatedList | 'Range:' descriptionAnnotatedList | 'Characteristics:' objectPropertyCharacteristicAnnotatedList | 'SubPropertyOf:' objectPropertyExpressionAnnotatedList | 'EquivalentTo:' objectPropertyExpressionAnnotatedList | 'DisjointWith:' objectPropertyExpressionAnnotatedList | 'InverseOf:' objectPropertyExpressionAnnotatedList | 'SubPropertyChain:' annotations objectPropertyExpression 'o' objectPropertyExpression { 'o' objectPropertyExpression } } objectPropertyCharacteristic ::= 'Functional' | 'InverseFunctional' | 'Reflexive' | 'Irreflexive' | 'Symmetric' | 'Asymmetric' | 'Transitive' dataPropertyFrame ::= 'DataProperty:' dataPropertyIRI { 'Annotations:' annotationAnnotatedList | 'Domain:' descriptionAnnotatedList | 'Range:' dataRangeAnnotatedList | 'Characteristics:' annotations 'Functional' | 'SubPropertyOf:' dataPropertyExpressionAnnotatedList | 'EquivalentTo:' dataPropertyExpressionAnnotatedList | 'DisjointWith:' dataPropertyExpressionAnnotatedList } annotationPropertyFrame ::= 'AnnotationProperty:' annotationPropertyIRI { 'Annotations:' annotationAnnotatedList } | 'Domain:' IRIAnnotatedList | 'Range:' IRIAnnotatedList | 'SubPropertyOf:' annotationPropertyIRIAnnotatedList individualFrame ::= 'Individual:' individual { 'Annotations:' annotationAnnotatedList | 'Types:' descriptionAnnotatedList | 'Facts:' factAnnotatedList | 'SameAs:' individualAnnotatedList | 'DifferentFrom:' individualAnnotatedList } fact ::= [ 'not' ] (objectPropertyFact | dataPropertyFact) objectPropertyFact ::= objectPropertyIRI individual dataPropertyFact ::= dataPropertyIRI literal misc ::= 'EquivalentClasses:' annotations description2List | 'DisjointClasses:' annotations description2List | 'EquivalentProperties:' annotations objectProperty2List | 'DisjointProperties:' annotations objectProperty2List | 'EquivalentProperties:' annotations dataProperty2List | 'DisjointProperties:' annotations dataProperty2List | 'SameIndividual:' annotations individual2List | 'DifferentIndividuals:' annotations individual2List | 'HasKey:' description annotations ( objectPropertyExpression | dataPropertyExpression ) { objectPropertyExpression | dataPropertyExpression }

2.6 Global Concerns

3 Quick Reference

This is a made-up partial ontology that provides a quick reference guide to the Manchester Syntax. Not all of the ontology makes logical sense so that all aspects of the syntax can be shown in a small example.

All colon-terminated keyword constructs except Ontology: (e.g., Import:, Class:, Domain:, SubClassOf:) are optional and can be repeated. Most keyword constructs take a comma-separated list of sub-constructs, which is sometimes indicated by ",...". Annotations are allowed for elements in these lists of sub-constructs except where annotations are explicitly noted (e.g., in DisjointUnionOf:, in DisjointClasses:).

4 Appendix: Translation to and from OWL 2 Functional-Style Syntax

4.1 Informal Description

In many cases there is a one-to-one correspondence between the Manchester OWL syntax and the OWL 2 Functional-Style Syntax. For example, dataComplementOf in the Manchester OWL syntax corresponds directly to dataComplementOf in the OWL 2 Functional-Style Syntax. All that is required is to translate the keywords and adjust to a parenthesized syntax.

IRIs and their parts are the same in the Manchester OWL syntax and the OWL 2 Functional-Style Syntax, no change is needed for them, except that the "special" datatypes are translated into the corresponding XML Schema datatypes. Literals are mostly the same, but the abbreviated syntaxes for numbers and strings have to be translated in the obvious way. The syntax for data ranges in the Manchester OWL syntax corresponds exactly with the syntax in the OWL 2 Functional-Style Syntax.

The syntax for annotations in the Manchester OWL syntax closely corresponds to the syntax in the OWL 2 Functional-Style Syntax. The only special processing that needs to be done is to determine which frame to attach entity annotations to in the reverse mapping. Translating to the Functional-Style syntax and back again can thus loose some non-logical information in the Manchester syntax.

Descriptions also correspond closely between the Manchester OWL syntax and the OWL 2 Functional-Style Syntax.

The translation of frame axioms is performed by splitting them into pieces that correspond to single axioms. This is done by taking each of the pieces of the frame (Annotations:, Domain:, Range:, etc) and making new frames for each of them. The new frame is of the same kind (Class:, ObjectProperty:, etc.) and for the same IRI. Then each resultant frame that contains an AnnotatedList with more than one element is broken into a frame for each element of the list in a similar manner.

The resultant axioms and any miscellaneous axioms then correspond closely to the OWL 2 Functional-Style Syntax axioms and can be directly translated. The only special cases are that annotations directly in frames become annotations in entity annotation axioms and that (negative) property assertions have to be disambiguated depending on whether the property is an object property or a data property.

Translations of OWL 2 Functional-Style Syntax axioms back to frames can be done piecemeal or the axioms on a single entity can be all combined together, which is done here.

The remaining top-level constructs of an ontology (namespaces, imports, ontology annotations, and the ontology name) can be directly translated.

4.2 Formal Description for Mapping to OWL 2 Functional-Style Syntax

Formally the transformation takes an ontology in the Manchester OWL syntax and produces an ontology in the Functional-Style syntax. The transformation needs access to the imported ontologies.

First, for each frame in the ontology, produce the appropriate declaration as follows:

Second, split up frames into single axioms in three stages. The first stage splits apart top-level pieces of frames that have multiple top-level pieces, transforming F: IRI p1 p2 ... into F: IRI p1 F: IRI p2 ... for F: one of the frame keywords (Class:, ...), until no more transformations are possible. The second stage splits apart the pieces of each of the top-level pieces, transforming F: IRI P: s1 s2 ... into F: IRI P: s1 F: IRI P: s2 ... for P: one of the keywords immediately inside a frame (Annotations:, SubClassOf:, ...), until no more transformations are possible. The third stage just removes any frame containing only a IRI.

Next, perform the actual syntax transformation. Any piece of syntax with no transformation listed here is just copied through.

Finally, put the declarations produced in the first step into the ontology.

4.3 Formal Description for Mapping from OWL 2 Functional-Style Syntax

The mapping from the Functional-Style Syntax back to the Manchester Syntax essentially just runs the above translation in reverse.

First, create a trivial frame containing only a IRI for each declaration in the ontology. Second, turn the Functional-Style Syntax into the Manchester Syntax by running the syntax transformation above in reverse. The non-determinism in the mapping of entity annotations is resolved by uniformly making them annotations in individual frames. Third, collapse frames for the same entity into one frame by running that part of the forward transformation in reverse. This step does not affect the meaning of an ontology and is thus optional.

5 Appendix: Internet Media Type, File Extension and Macintosh File Type

Contact

Sandro Hawke

See also

How to Register a Media Type for a W3C Specification Internet Media Type registration, consistency of use TAG Finding 3 June 2002 (Revised 4 September 2002)

The Internet Media Type / MIME Type for the OWL Manchester Syntax is "text/owl-manchester".

It is recommended that OWL Manchester Syntax files have the extension ".omn" (all lowercase) on all platforms.

It is recommended that OWL Manchester Syntax files stored on Macintosh HFS file systems be given a file type of "TEXT".

The information that follows will be submitted to the IESG for review, approval, and registration with IANA.

6 References