Explanation:
y <= x/2 + 2
the maximum is to have 2 boondins and add 1/2 boondin every day.
but every time Mimstoon did not use the max. possible, the resulting total sum of boodins stays smaller that the maximum, and is therefore a valid data point.
(6, 7) is not in the inequality relationship.
because the max. boondins after 6 days is 2 (from the beginning) and 1/2 every day = 2 + 1/2 × 6 = 2 + 3 = 5.
but the data point shows 7 as y value (which is larger than the allowed max. of 5).
therefore the inequality is false for this data point, and therefore the data point is not in the inequality relationship.