Allows observation of the execution of an NCL procedure from an external source, that is, another environment, another user region, window, or NCL environment.
Eliminates the need for code changes to debug a procedure. For example, there is no need to add &CONTROL or &WRITE statements.
Provides comprehensive control over the NCL procedure as it is being executed, supporting statement stepping, alteration of variable contents and attributes, and so on.
Allows specification of criteria for debugging, before the target NCL begins execution.
