 be correct if both heap and
&gt; &gt;grain have unchanging definitions.
&gt; 
&gt; No, I insist. Stop being an engineer or a logician for a second and
&gt; imagine you are a kid again. Isnt is just *obvious* that heaps can be
&gt; large and can consist of humungous numbers of small grains, that
&gt; taking just one grain away is never going to make a large heap not
&gt; large, yet taking enough of them away will eventually do it. And that
&gt; combination of facts isn't at all puzzling or mysterious: its j