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This article explores feature structures as functions, which are sets of ordered pairs of attributes and values. It discusses the properties of feature structures and provides examples to illustrate their usage.
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Attributes and values The following object describes a class of persons:
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian Attributes
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian Values Attributes
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian Let this be the class of persons described:
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian Let this be the class of persons described:
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian Let this be the class of persons described: Then remove a feature...
Attributes and values The following object describes a class of persons: age 22 nationality Norwegian Let this be the class of persons described: Then remove a feature...
Attributes and values The following object describes a class of persons: age 22 nationality Norwegian Let this be the class of persons described: Then remove a feature... and the class grows.
Attributes and values The following object describes a class of persons: age 22 nationality Norwegian Let this be the class of persons described: Then remove a feature... and the class grows. Add a feature instead...
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian eyecolour brown Let this be the class of persons described: Then remove a feature... and the class grows. Add a feature instead...
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian eyecolour brown Let this be the class of persons described: Then remove a feature... and the class grows. Add a feature instead... and the class shrinks.
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian A grammar example:
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian A grammar example: cat NP number sg person 3
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian A grammar example: cat NP number sg person 3 This object describes a class of phrases:
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian A grammar example: cat NP number sg person 3 This object describes a class of phrases: a man the horse some red car the King’s man water nice beer ...
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian A grammar example: cat NP number sg person 3 This object describes a class of phrases: Remove a feature... a man the horse some red car the King’s man water nice beer ...
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian A grammar example: cat NP person 3 This object describes a class of phrases: Remove a feature... a man the horse some red car the King’s man water nice beer ...
Attributes and values The following object describes a class of persons: age 22 gender M nationality Norwegian A grammar example: cat NP person 3 This object describes a class of phrases: Remove a feature... and the class grows. men the horses some red cars the King’s men waters nice beers ... a man the horse some red car the King’s man water nice beer ...
Feature structures as functions cat NP number sg person 3 f1:
Feature structures as functions cat NP number sg person 3 f1: • A set of ordered pairs (of attributes and values)
Feature structures as functions cat NP number sg person 3 f1: • A set of ordered pairs (of attributes and values) • Never more than one occurrence of a given attribute
Feature structures as functions cat NP number sg person 3 f1: • A set of ordered pairs (of attributes and values) • Never more than one occurrence of a given attribute • Never more than one value of a given attribute (but different attributes can have the same value)
Feature structures as functions cat NP number sg person 3 f1: • A set of ordered pairs (of attributes and values) • Never more than one occurrence of a given attribute • Never more than one value of a given attribute (but different attributes can have the same value) • Hence such a structure can be considered asa function from attributes to values
Feature structures as functions cat NP number sg person 3 f1: • A set of ordered pairs (of attributes and values) • Never more than one occurrence of a given attribute • Never more than one value of a given attribute (but different attributes can have the same value) • Hence such a structure can be considered asa function from attributes to values • Example: • f1(cat)=NP • f1(number)=sg • f1(person)=3
Feature structures as functions cat NP number sg person 3 f1: • A set of ordered pairs (of attributes and values) • Never more than one occurrence of a given attribute • Never more than one value of a given attribute (but different attributes can have the same value) • Hence such a structure can be considered asa function from attributes to values • Example: • f1(cat)=NP • f1(number)=sg • f1(person)=3 • Values can be atomic or complex:
Feature structures as functions cat NP number sg person 3 f1: • A set of ordered pairs (of attributes and values) • Never more than one occurrence of a given attribute • Never more than one value of a given attribute (but different attributes can have the same value) • Hence such a structure can be considered asa function from attributes to values • Example: • f1(cat)=NP • f1(number)=sg • f1(person)=3 • Values can be atomic or complex: cat NP number singular person third agreement
Subsumption cat NP
Subsumption cat NP cat NP agreement number singular
Subsumption cat NP cat NP agreement number singular cat NP number singular person third agreement
Subsumption cat NP number singular person third agreement cat NP number singular person third subject cat NP agreement number singular cat NP number singular person third agreement
1 1 Subsumption cat NP number singular person third agreement cat NP number singular person third subject cat NP agreement number singular cat NP number singular person third agreement cat NP number singular person third agreement subject
Not subsumption cat NP 1 agreement number singular
Not subsumption cat NP 1 agreement number singular cat NP 2 agreement person third
Not subsumption cat NP 1 2, 2 1 1 agreement number singular cat NP 2 agreement person third
Not subsumption cat NP 1 2, 2 1 1 agreement number singular cat NP 2 agreement person third cat NP 3 agreement number plural
Not subsumption cat NP 1 2, 2 1 1 3, 3 1 1 agreement number singular cat NP 2 agreement person third cat NP 3 agreement number plural
Not subsumption cat NP 1 2, 2 1 1 3, 3 1 1 agreement number singular cat NP 2 agreement person third cat NP 3 agreement number plural cat NP 4 number singular person third agreement
Not subsumption cat NP 1 2, 2 1 1 3, 3 1 1 4 1 agreement number singular cat NP 2 agreement person third cat NP 3 agreement number plural cat NP 4 number singular person third agreement
Not subsumption cat NP 1 2, 2 1 1 3, 3 1 1 4 2 4 1 agreement number singular cat NP 2 agreement person third cat NP 3 agreement number plural cat NP 4 number singular person third agreement
Not subsumption cat NP 1 2, 2 1 1 3, 3 1 1 4 2 4 1 2 = 4 1 agreement number singular cat NP 2 agreement person third cat NP 3 agreement number plural cat NP 4 number singular person third agreement
Not subsumption cat NP 1 2, 2 1 1 3, 3 1 1 4 2 4 1 2 = 4 1 3 = fail 1 agreement number singular cat NP 2 agreement person third cat NP 3 agreement number plural cat NP 4 number singular person third agreement
Not subsumption cat NP 1 2, 2 1 1 3, 3 1 1 4 2 4 1 2 = 4 1 3 = fail Unification: ab = c if and only if a c and b c and there is no d such that a d and b d and d c 1 agreement number singular cat NP 2 agreement person third cat NP 3 agreement number plural cat NP 4 number singular person third agreement