Eubulides of Miletus (IV century BC) formulated a logical paradox associated with the ambiguity of the concept of "heap". If you add one grain at a time, from what moment will the pile appear, and does this mean that the pile is the result of adding one grain?
One grain does not form a heap and the addition of one grain to an aggregate that is not a heap is not essential for the formation of a heap. Under such assumptions, no aggregate of an arbitrarily large number of grains will form heaps, which contradicts the concept of the existence of a heap of grains.
A pile of sand is made up of millions of grains of sand. If you remove one grain of sand, it will still be a heap. If you remove one more, then it will still be a bunch. If we continue to remove one grain of sand until there is one grain of sand left, will it still be a heap? A fixed limit must be set for the solution. If we assume that 10,000 grains of sand is a heap, then anything less than this will not be a heap. But it does not seem justified to distinguish between 9,999 and 10,001 grains of sand. Then you can expand the solution by saying that there is a certain boundary, but it is not necessarily known.
The paradox is used as one of the justifications for considering fuzzy logic.
The essence of the paradox is that quantitative changes do not lead to qualitative changes.