Debug mode
Debug mode changes how some functions and calculations behave in order to assist the diagnosis of errors (bugs) when writing custom calculations. Some calculations may alter their behaviour when debug mode is enabled, therefore debug mode should always be disabled when producing final output calculations.
Log all expressions
When calculating is in progress, tracing will log messages that help you to monitor the execution sequence of your calculations, to detect malfunctions. The messages that tracing produces appear in the Progress Log window therefore the Progress Log must be enabled to read the messages.
Delete temporary variables when finished calculating
Normally when the calculation process has finished all variables which have the temporary attribute enabled will be automatically deleted, enableing this options prevents them from being deleted.
Cache Calc Libraries
Normally during the calculation process when a Calc Library is opened it will remain open until the calculation process has finished in order to improve the speed of calculating. When a library is open in the cache it cannot be modified therefore if you want to to modify calculations whilst they are running you can disable this setting.