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Concepts
This section of the documentation covers the use of Objects, Libraries and References, Notations, Styles and Types and how each is created, edited and used in the Sym application.
Objects
An object is the basic building block of all of the symbolic content contained in a document - every term in every symbolic expression in Sym is an instance of an object. Many of the objects used in Sym have an object definition that specifies how the object looks and behaves, but it's also possible to create objects that don't have object definitions. All objects are identified by their name and object names are always defined in a specific namespace. All object definitions contain a type definition. Optionally, objects can also contain Properties, Clauses, Renderings, and a Description.
Property Objects
Function Properties
These properties are intended to be used in object definitions that are also functions (have clauses included in the object definition).

Concepts
This section of the documentation covers the use of Objects, Libraries and References, Notations, Styles and Types and how each is created, edited and used in the Sym application.
- Objects
  An object is the basic building block of all of the symbolic content contained in a document - every term in every symbolic expression in Sym is an instance of an object. Many of the objects used in Sym have an object definition that specifies how the object looks and behaves, but it's also possible to create objects that don't have object definitions. All objects are identified by their name and object names are always defined in a specific namespace. All object definitions contain a type definition. Optionally, objects can also contain Properties, Clauses, Renderings, and a Description.
  - Object Modules
    An Object Module contains object definitions. Object definitions contain the name, type definition, renderings, code and properties that define the functionality of every object. Object Modules are created, edited and managed using the Document Explorer.
  - Creating and Editing Objects
  - Objects Used in Code
    Objects that are commonly used in clauses in function are listed below.
  - Property Objects
    - Object Definition Properties
      These properties are normally used in the definitions of objects that are not either commands or functions.
    - Command Properties
      These properties are designed to be used on object definitions that define commands.
    - Function Properties
      These properties are intended to be used in object definitions that are also functions (have clauses included in the object definition).
  - Special Objects
  - Autogenerated Objects
  - Monoids
    Monoids are typically defined as a binary mapping that has an identity element and is associative. In the construction of the Sym application, we have taken an equivalent, but different approach to defining and handling monoids. It may be surprising to see something so fundamental defined in a non-standard way, so the reasoning for taking this approach is explained below.
- Library Locations and References
  Locations are used to manage groups of libraries and documents. The purpose of locations is to make documents portable from one machine to another. To do that, locations can be online as well as on your local machine. If a document references online libraries, the required libraries will be downloaded automatically when the document is opened.
- Notations and Rendering
  The purpose of notations is to make it possible to easily change the way expressions are displayed. Notations are assigned to Document Modules, Unit Test Modules and Object Modules. The notation assigned determines which renderings are selected for each expression in the module.
- Styles
  Each notation refers to a stylesheet. Stylesheets define Styles. Styles are used in two places. First, they can be used to style text. Second, they can be used to style parts of an expression in a rendering. You can create new style and new stylesheets.
- Types
  Every term in every expression in a Sym document has a type assigned to it. Every object definition has a type definition as one of its components. Since type definitions can include things like type variables, Sym uses a type inferencing process to determine the explicit types assigned to each term in every expression.

Function Properties

These properties are intended to be used in object definitions that are also functions (have clauses included in the object definition).


Property	Library	Usage
Autocomplete	Basics	Indicates that the object is an autocomplete definition. When building autocomplete lists, this function will be executed and the results will be inserted into the autocomplete list.
BuildAll	Basics	When this property is attached to an object definition, all of the clauses in the function are executed and the results are returned in a List object
Override	Basics	The Override property prevents clauses defined in extensions from base libraries from being included when the function is executed. By default, if an object definition has extensions, the clauses from all of the definitions are combined into a single list in the reverse order that the libraries appear in the Document Explorer. If an object definition has the Override property, then clauses from libraries higher up in the list in the Object Explorer are not included. In this case, clauses from the remaining object definitions can be invoked using the FunctionCall object. See Extending Object Definitions
ObjectGenerator	Core	An object definition with this property that is also a Sym function will be called during the build process and the results will be used to dynamically generate object definitions. An object definition with this property must have a type definition that has ObjectDefinition as its result type or an error will be generated during the build process. The ObjectModule provided as the first parameter is the name of the module in the Autogenerated Objects library where the autogenerated object definitions will be placed.