Grammar

This section describes the grammar of the E-HowNet expression.

Tokens

• TEXT

  • Any non empty string containing the following characters:

    • Alphabets and Numbers (A-Za-z0-9)

    • Unicode Characters (\x80-\U0010FFFF)

    • |, #.

• NUMBER

  • e.g. 1, 0.1, 1e-4

• COINDEX

  • x, x1, x2, …

• x? (refer to the unmentioned subject entity)

Nodes

Entity

Entities are basic elements in E-HowNet definition.

• EhnParseNormalEntity

  A normal entity.

  • Syntaxes:

    • {TEXT}

    • {TEXT:FEATURE}

    • {TEXT:FEATURE,FEATURE}

    • {TEXT:FEATURE,FEATURE,...}

    • {TEXT_COINDEX}

    • {TEXT_COINDEX:FEATURE}

    • {TEXT_COINDEX:FEATURE,FEATURE}

    • {TEXT_COINDEX:FEATURE,FEATURE,...}

  • Description:

    • TEXT is the head (the label of the inherited concept) of this entity.

    • FEATUREs are the additional features to this entity.

    • COINDEX is the anchor of this entity for further reference.

  • Example:

    {human|人:kind={other|另}}

• EhnParseFunctionEntity

  An entity with function as its head.

  • Syntaxes:

    • {FUNCTION}

    • {FUNCTION:FEATURE}

    • {FUNCTION:FEATURE,FEATURE}

    • {FUNCTION:FEATURE,FEATURE,...}

    • {FUNCTION_COINDEX}

    • {FUNCTION_COINDEX:FEATURE}

    • {FUNCTION_COINDEX:FEATURE,FEATURE}

    • {FUNCTION_COINDEX:FEATURE,FEATURE,...}

  • Description:

    Similar to normal entity, but replace the head by a function (FUNCTION) of entity/entities.

• EhnParseNameEntity

  A “name”.

  • Syntaxes:

    • {"TEXT"}

  • Example:

    • {country|國家:location={Europe|歐洲},quantifier={definite|定指},name={"英國"}}

      The name of this country is 英國.

• EhnParseNumberEntity

  A number.

  • Syntaxes:

    • {NUMBER}

  • Example:

    • {month|月:sequence={1}}

      The sequence of this mouth if 1.

Reference

References refer to other entities.

• EhnParseCoindexReference

  Refers to previous mentioned entity.

  • Syntaxes:

    • {COINDEX}

  • Description:

    • Refers to the entity with anchor _COINDEX.

    • If _COINDEX does not exist, represent that all {COINDEX} with the same name are the same placeholder.

  • Example:

    • {A_x1:r={B:b={x1}}}

      {x1} refers to {A_x1:...}.

    • {vehicle|交通工具_x1:predication={fly|飛:theme={x1}}}

      {x1} refers to {vehicle|交通工具_x1:...}.

• EhnParseSubjectReference

  Refers to unmentioned subject entity.

  • Syntaxes:

    • {x?}

  • Example:

    • r={B:b={x?}}

      {x?} refers to the unmentioned subject entity S with the following attribute {S_x1:r={B:b={x1}}}.

    • 現役: predication={當兵|ServeInArmy:agent={x?},aspect={Vgoingon|進展}}

      {x?} refers to the unmentioned subject entity S. For example, the word 軍人 of 現役軍人.

• EhnParseTildeReference

  Refers to the root entity.

  • Syntaxes:

    • {~}

  • Example:

    • {A:r={B:b={~}}}

      {~} refers to {A:...}.

    • {vehicle|交通工具_x1:predication={fly|飛:theme={~}}}

      {~} refers to the root entity {vehicle|交通工具_x1:...}.

  Note

  Deprecated since version 3.0.

Placeholder

Placeholders represent any entities under the given restriction.

• EhnParseRestrictionPlaceholder

  A restriction placeholder.

  • Syntaxes:

    • /ENTITY

    • /ENTITY_COINDEX

  • Description:

    • ENTITY shows that this node can be replace by any hyponymy/instance(s) of the ENTITY.

    • COINDEX is the anchor of this restriction for further reference.

  • Example:

    • {CentrePart(/{place|地方})}

      The argument of CentrePart must be a hyponymy/instance of place|地方.

• EhnParseAnyPlaceholder

  A placeholder without restriction.

  • Syntaxes:

    • {}

  • Description:

    Represent a placeholder without any restriction. Only used as the value of a feature.

  • Example:

    • feature={}

      {} represent that the value of this feature can be any entity.

Feature

Features provides extra information to entities.

• EhnParseNormalFeature

  A normal feature.

  • Syntaxes:

    • TEXT=ENTITY

    • TEXT=REFERENCE

    • TEXT=RESTRICTION

    • TEXT={}

  • Description:

    • TEXT is the head (the name) of the this feature.

    • ENTITY/RESTRICTION is the value of this feature.

  • Example:

    • {thing|萬物:qualification={concrete|具體}}

      The qualification of thing|萬物 is concrete|具體. Here qualification={concrete|具體} is a normal feature.

• EhnParseFunctionFeature

  A function feature.

  • Syntaxes:

    • FUNCTION=ENTITY

    • FUNCTION=REFERENCE

    • FUNCTION=RESTRICTION

    • FUNCTION={}

  • Description:

    Similar to normal feature, but replace the head by a function (FUNCTION) of entity/entities.

  • Example:

    • {animate|生物:ability({SelfMove|自移})={very|很}}

      The ability of SelfMove|自移 of animate|生物 is very|很. Here ability({SelfMove|自移})={very|很} is a function feature.

Function

Functions act on entities.

• EhnParseFunction

  A function of entity/entities or restriction.

  • Syntaxes:

    • TEXT()

    • TEXT(RESTRICTION)

    • TEXT(ENTITY)

    • TEXT(ENTITY,ENTITY)

    • TEXT(ENTITY,ENTITY,...)

  • Description:

    • TEXT is the head (the name) of the this function.

    • ENTITYs are the arguments of this function; every ENTITY can be replaced by a REFERENCE.

    • RESTRICTION represent that the arguments of this function can be anything under this restriction.

    • TEXT() represent that the arguments of this function can be any entity/entities.

  Note

  TEXT({}) is not valid. Use TEXT() instead.

Valid Expressions

A valid expression can be an ENTITY or any number of FEATUREs joined by ,s.

• ENTITY

• FEATURE

• FEATURE,FEATURE

• FEATURE,FEATURE,...