Predefined types

It is not allowed to declare predefined types. They can be used to declare composite types (see Composite types on page 25) or generic types (see Generic types on page 29). Predefined types are members of the type class ATTRIBUTE. The predefined types of the HDSL are  

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These constraints simply navigate parameterized attributes we could use the more conventional syntax a < b instead of a.isLessThan(b). Thus, a predefined type Date has a parameterized attribute < (Date) Boolean, which yields true or false for any given compared date. 

This is a common form of specification for exceptions, so we introduce a convenient query isException on the predefined type Boolean and rewrite it as... 

Domain-specific knowledge is formalized by a process model definition (cf. Sect. 2.4) which constrains the process model instances to be maintained at project runtime. As a consequence, the manager may compose task nets from predefined types and relationships. The process model definition is represented in the Unified Modeling Language UML [560]), a wide-spread standard notation for object-oriented modeling. A process model is defined on the type level by a class diagram which has been adapted to the underlying process meta model for dynamic task nets [388, 389]. 

An object model-based query interface to ArrayExpress is being developed. The Web interfaces for predefined types of queries will be provided on top of the general query mechanism. For the database to be used for efficient data mining and interactive visualization, extensive optimization may be required, e.g., by tuning of table indexing or producing a denormalized database schema for some parts of the database. 

Each model can have parameters, variables, equations, initial conditions, boundary conditions and submodels that can have submodels themselves. Models can be based in pre-existing ones, and extra-functionality (new parameters, variables, equations, etc.) can be added. So, composition hierarchical modelling) and inheritance are supported. Every parameter and variable in a model is based in a predefined type and have a set of properties like a line/description, lower and upper bounds, unit of measurement among others. As models, types can have subtypes and the object-oriented paradigm is implemented. Some examples of types declarations can be seen in Figure 2. 

The CACTVS system is probably the first instance of a general-purpose chemical data handling package designed to operate in a networked environment. In contrast to special-purpose chemistry-related software, this system is not limited to working with a fixed set of information (analysis of some predefined type of information, computation of some values. 

Electronic modules called electronic safety relay subsequently appeared, implementing predefined-type schematics, which are easier to wire, and integrating summary diagnosis. These modirles are widely used in the manufacturing sector for the management of emergency stop, zone control by immaterial barriers, or for the... 

The term "parametric models" expresses the capability of certain CAD systems which allows the CAD system user to assign values to elementary data of some predefined type with the consequence that this will influence the CAD model in a certain way. A typical example is the length of some dimension in a model that is defined not as a constant but as a variable which has some value. Assignment of a new value to this length will cause a redefinition of all geometry that depends on this variable. The reference model allows the use of either constant values for predefined types, or references to entities of predefined type. 

User records are provided as a standard way for escaping from the restrictions of the schema when needed. User records are not semantically known in the reference model. They can be accommodated there as a means of storing information that is to be associated with entities, but that is to be interpreted only by special programs. User records may contain data of predefined type only. The record structure may be controlled by a special user-type record. 

The following example defines an illegal class type, because the second element of the class is neither a predefined type, nor a type name, nor type instance ... 

USER DEFINED NAME, STRING or LOGICAL, then ATTRIBUTE TYPE is translated into the corresponding tokens. If ATTRIBUTE TYPE denotes the predefined type ARITHMETIC EXPRESSION, then ATTRIBUTE TYPE is translated into <arithmetic expression> (see "Arithmetic expressions" on page 162). 

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