<Dd> 7006100000000000000 ♠ 1000000 grains is a heap . </Dd> <Dd> If 7006100000000000000 ♠ 1000000 grains is a heap then 7005999999000000000 ♠ 999 999 grains is a heap . </Dd> <Dd> So 7005999999000000000 ♠ 999 999 grains is a heap . </Dd> <Dd> If 7005999999000000000 ♠ 999 999 grains is a heap then 7005999998000000000 ♠ 999 998 grains is a heap . </Dd>

When does a pile of sand stop being a pile