If you have four grains of sand arranged in a tetrahedron, you could conceivably call it a (very small) heap. When you take away one of the grains, you will no longer have a heap, just three grains of sand.
This is assuming that your definition of “heap” includes some of it being on top of the rest of it, which I’m fairly sure is standard.
If you have four grains of sand arranged in a tetrahedron, you could conceivably call it a (very small) heap. When you take away one of the grains, you will no longer have a heap, just three grains of sand.
This is assuming that your definition of “heap” includes some of it being on top of the rest of it, which I’m fairly sure is standard.
That’s what I would have said.