icon-color: For items of system-defined classes that have an iconic representation style, this is both the name of a color attribute and an icon region.
Icon Size Indicator: In the Icon Editor, a display that shows the size of the icon in workspace units.
ICP (Intelligent Communications Protocol): Gensym's proprietary communications protocol, which allows G2s, G2 Gateways, and Telewindows to share information and distribute control among one or more G2 processes. ICP is a layer built on top of the DECnet or TCP/IP networking protocols, depending on which platforms you are using in your network.
identical definitions: Identical items that are class definitions. Contrast with duplicate definitions.
identical items: Items that are the same in every respect whatsoever. The tables of two identical items are indistinguishable. Contrast with duplicate items.
image: A bitmap or other graphical image created outside G2. You can use an external image as part of an icon, or as the background of a workspace.
Image Indicator: In the Icon Editor, a display that shows the name of an externally defined image that is included in a layer.
immediate class: In a discussion of a class and its properties, the class that is the subject of the discussion.
immediate drawing: One of two drawing modes. When drawing is immediate, G2 updates the display as soon as some visible change is made to the KB, either interactively or programmatically. Drawing in immediate mode temporarily defers other KB processing until drawing is complete. Contrast with scheduled drawing.
implicit local name: An undeclared local name.
independent-for-all-compilations: One of two G2 compilation configurations. For an item whose attributes refer to another item that is declared stable-for-dependent-compilations, this configuration directs G2 not to compile the item to take advantage of the other item's stability. Contrast with stable-for-dependent-compilations.
indexed attribute: A user-defined attribute whose value G2 retrieves using an internally maintained hash table. G2 can perform efficient searches to locate an item of a user-defined class by a particular value of one of its indexed attributes.
inference engine: The G2 component that monitors events and reasons about changing conditions while invoking rules by means of forward chaining, backward chaining, event detection, focusing, and scanning.
inheritance: An important property of object-oriented development environments. A class inherits the attributes of its superior. Inheritance facilitates rapid development, eliminates redundancy in an application, and builds reusable application components.
inherited attributes: Attributes that a class has by inheriting them, rather than by defining them in the class's definition.
initial value: The value that a variable or parameter has on instantiation. Resetting G2 restores this value. See also default value.
initialization mode: A GFI input mode that typically provides a KB with values read in as soon as the KB begins execution.
input interface object: Used by GFI to read data from an external data file and to provide data service for variables and parameters in a knowledge base.
Inspect facility: A component of the G2 developer's environment that supports searching for items based on their type, class, attributes, and location. When Inspect locates an item, you can conveniently navigate to it or simply modifying its attributes using an attribute table. To open the Inspect facility, select the
Inspectchoice on the Main Menu.
Inspect workspace: The workspace that displays the results of Inspect commands.
installed system tables: The system tables whose values are in effect for the current KB. In a modularized KB, there are as many sets of system tables as there are modules; however, only one set of system tables is installed at a time.
instance: One of a class of items, for example,
pump-1is instance of the pump class.
instance configuration: A configuration whose scope is determined by the current KB's class hierarchy. Instance configuration statements are contained in the
Instance-configurationattribute of an object, connection, and message definition. Contrast with item configuration.
instantiate: To create an instance of one or more classes.
Intelligent Communications Protocol: See ICP.
interface object: An object that GFI uses as an interface between a knowledge base and an external data file.
interpolated value of expression: The interpolated value of a variable or parameter at some time in the past. G2 performs a straight-line interpolation and requires that you keep a history of the values for the parameter or variable.
inverse relation: A relation between the relation object (the second class) and the relation source (the first class), as defined in a relation definition. You specify the name of the inverse relation in a relation definition's
item: An entity in G2 that represents a set of knowledge that has identity and that persists. Each item represents a set of information that is distinct from other information and that you can reference directly or indirectly.
item configuration: A configuration whose scope is determined by the current KB's workspace (or containment) hierarchy. Item configuration statements are contained in the
Item-configurationattribute of any item. Contrast with instance configuration.
item hierarchy: The hierarchy of the item class and its subclasses.
item layer position: For an item upon a workspace, the relative position of an item on top of or beneath other items that are upon the same workspace.
item layering: Whether items upon the same workspace appear on top of or beneath each other.
item passing: For G2 to G2, or G2 to a bridge process, the ability to pass a copy of any item as a reference, using a network handle.