Probably worth bearing in mind that 'active' is a user-assigned status and not a calculated one.

The user chooses whether a project is active |done|dropped|on hold and the filter system works with these atoms of user choice, and other factors like user-specified dates, to derive computed states like 'Remaining' or 'Stalled' (without overwriting the user's status or date data).

The draft FAQ on OF 1.8 filter options may give an idea of how the atoms of user-assigned status, dates etc are combined logically to build the filter rules.

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