Example, I have a task to check if two data points are equal. Then I have a follow-on task to update the older of the two data points, if they are unequal.

It seems I could delete the second task if it is unnecessary (when the data points are equal). But it would be preferable to have the second task be conditional upon the first task. Perhaps you could mark a task with Yes/No completion options, and a second task would appear as "Cancelled" if the first task was marked "No" but would appear as "Incomplete" if the first task was marked "Yes".