The puzzle can be expressed as an argument most simply using modus ponens:
P1. 1 grain of wheat does not make a heap.
P2. 1 grain doesn’t make a heap, then 2 grains don’t.
P3. If 2 grains don’t make a heap, then 3 grains don’t.
C. If 999,999 grains don’t make a heap, then 1 million grains don’t.-Hyde, Dominic and Diana Raffman, “Sorites Paradox“, The Stanford Encyclopedia of Philosophy (Summer 2018 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/sum2018/entries/sorites-paradox/>.
The Sorities Paradox reveals another facet of the limits of categories. How many grains is in a heap? How much hair do you need on your head to not be bald?