category: A named association of rules. To associate a rule with a rule category, enter a non-reserved symbol in the rule's
Categoriesattribute; this names a rule category and associates the rule with that category. Use the
invokeaction to invoke all rules for a category.
causal knowledge: Knowledge about cause and effect relationships.
class: A group of items that have the same icon, attributes, and behavior. Classes are organized into a hierarchy, in which each class inherits the attributes of its superior class, but may have additional attributes of its own.
class hierarchy: A hierarchical structure of class definitions that is built into G2, but can be extended by the user.
class inheritance path: A linear list of all the classes from which a class inherits.
class list workspace: A particular kind of workspace that presents lists of classes, items, or other entities for entering in the Text Editor.
class-specific attribute: An attribute that is specified by a class's definition, rather than inherited from the definitions of its superior classes.
clock tick: The fundamental unit of time within G2. The time interval of each clock tick is determined by the user-settable
Minimum-scheduling-intervalattribute of the Timing Parameters system table.
collection time: The instant in time when a variable or parameter receives a value. For a variable, G2 uses this value and the variable's validity interval to determine an expiration time for each collected value.
color attribute: A named portion of an item's knowledge that can have a color value, such as the
background-colorcolor attribute of workspaces. Color attributes do not appear in the attribute tables of items.
Color Indicator: In the Icon Editor, a display that names the color of the current layer.
command line option: Included in the operating system command that launches a new G2 process, this keyword affects how the new G2 starts and runs.
compilation configuration: A configuration that affects how G2 compiles attributes that refer to classes, items, and attributes.
compilation dependency: A relationship between an item with compiled attributes and other items, where the item's compiled attributes refer to the knowledge of those items.
compiled attribute: An attribute that can contain an expression, an action, or a statement.
component: For a trend chart, a building block that customizes a charting feature or a representation of data.
component reference: In a trend chart, the number or name by which you specify a particular component of a compound attribute.
component subtable: One method of displaying compound attribute components in trend charts. A component subtable lists all of the component attributes, and provides a means of interactively customizing a component.
composite attributes: Attributes that appear in an attribute table as one attribute, but which are composed of more than one subattribute.
compound attribute: One or more components in a trend chart.
concrete class: User- or system-defined class that can be instantiated. Contrast with abstract class.
concrete type: An actual value must be of a concrete type. G2 offers these concrete types:
truth-value. G2 also offers system-defined operators that work with values of concrete types. Contrast with abstract type.
concurrent execution: The process of executing statements, including actions, in parallel. When G2 executes a set of statements concurrently, the result is as if all statements had executed at the same time. Contrast with sequential execution.
configuration: A declaration that changes the default behavior of items.
conflict workspace: A permanent, named workspace that G2 creates and displays after loading two or more modularized KB files, or after merging a KB file into the current KB, where definitions of classes differ among the loaded KB files.
connection post: An object that you use to draw a connection from one workspace to another, from one object to another object on its subworkspace, or across a single workspace. G2 considers that items connected to two connection posts with the same name are also connected to each other.
consequent: In a rule, the phrase that specifies one or more actions for G2 to perform, either sequentially or simultaneously. G2 performs these actions only if evaluating the expression in the rule's antecedent produces a sufficient truth-value. Contrast with antecedent.
consistently modularized: A KB file or the current KB is consistently modularized when: every module is named in its own Module Information system table; there is only one module that is not directly required by any other module; every top-level workspace is associated with a module; for each attribute table that is transferred to a workspace, that workspace and the table's superior item are associated with the same module; modules containing definitions are directly required by all modules that contain instances of those definitions's classes; there are no cyclic dependencies in the module hierarchy. Contrast with unmodularized.
current KB: The items contained in the memory of a running G2 process.
current knowledge: The parts of an item's knowledge that have been updated since the current KB started. G2 discards the current knowledge of items when you reset or restart the current KB, or when you save the current KB to a KB file. Contrast with permanent knowledge.
current language: An existing language translation item (or the symbol
english) that G2 uses to display the names of menus and menu choice text (and for some languages, a custom Text Editor interface) in the G2 developer's environment. Contrast with default language.
current layer: In the Icon Editor, the layer that is being edited. The current layer is indicated by a heavy border.
current scale: For a workspace, the scale at which G2 displays that workspace, which is a factor of its default scale. By specifying a new current scale, you can interactively or programmatically change the displayed size of a workspace. Contrast with default scale.
current task queue: The internal queue that the scheduler maintains for tasks currently eligible for execution. After G2 performs a task, the scheduler removes it from the current task queue.
Cursor Indicator: In the Icon Editor, a display that shows the current cursor position as x, y coordinates.
cyclic dependency: In a module hierarchy, the condition in which a module M is directly required by another module that module M directly or indirectly requires.