<fsDecl>

<fsDecl> (feature structure declaration) declares one type of feature structure. 18.11 Feature System Declaration
組件iso-fs — 18 Feature Structures
屬性
typegives a name for the type of feature structure being declared.
狀態 必備的
資料類型 
data.enumerated
值 any convenient string of characters.
baseTypesgives the name of one or more typed feature structures from which this type inherits feature specifications and constraints; if this type includes a feature specification with the same name as that of any of those specified by this attribute, or if more than one specification of the same name is inherited, then the set of possible values is defined by unification. Similarly, the set of constraints applicable is derived by combining those specified explicitly within this element with those implied by the baseTypes attribute. When no baseTypes attribute is specified, no feature specification or constraint is inherited.
狀態 非必備的
資料類型 1–∞ occurrences of 
data.name
以空白鍵隔開
值 one or more names as defined by the W3C XML Specification
註
Inheritance is defined here as a monotonous relation.
The process of combining constraints may result in a contradiction, for example if two specifications for the same feature specify disjoint ranges of values, and at least one such specification is mandatory. In such a case, there is no valid representative for the type being defined.
屬於fsdDecl
可包含
iso-fs: fDecl fsConstraints fsDescr
宣告
element fsDecl
{
   att.global.attributes,
   attribute type { data.enumerated },
   attribute baseTypes { list { data.name+ } }?,
   ( fsDescr?, fDecl+, fsConstraints? )
}