object passing: The ability to pass a copy of an object from one G2 process to another via an external interface. Object passing is accomplished through the use of a remote procedure declaration to specify which attributes of the object to send.
Off-line license: A fundamental G2 license type providing G2 for a stand-alone system.
On-line license: A fundamental G2 license type providing the capability to communicate or access other systems.
one-to-many: The cardinality of a relation, where one instance of the first class can be related to any number of instances of the second class.
one-to-one: The cardinality of a relation, where one instance of the first class can be related to, at most, one instance of the second class.
operand: In an expression, a term that participates in an arithmetic, class-qualified, concatenation, logical, or relational operation.
operation: In object-oriented programming, a function or transformation that can be applied to instances, typically in different ways for members of different classes.
operator: In an expression, a reserved symbol or character that specifies a type-specific operation.
Operator Logbook: A special workspace for displaying informational messages and signalling G2 errors. You control the placement and other properties of the logbook workspaces using the Logbook Parameters system table.
output frequency: In GFI, the interval at which to write data to a GFI output file.
output interface object: An object that GFI uses to obtain values from variables and parameters in a knowledge base and write them to an external data file.
overlay file: The output file created after using the Overlay utility, described next.
Overlay utility: A Gensym-provided utility for creating an overlay C source file from a template file as one of the steps in using foreign functions.