For each pillow there is a pillow cover
for each ___ there is a ___
This nondescript line from Exercise 1 (Conceptual Mathematics, page 306) is an excuse for pillow fights. It’s possible that two different pillows get assigned to the same one pillow cover, and pillows fighting over the cover inevitably follows and then there are pillow covers that no pillow wants (which is what got some people into ‘people is scenery’ theory of people).
for each f: D -> C there is a x: 1 -> X
is saying something like there is a function from a collection (of functions f from a domain set D to a codomain set C) to a collection (of elements x)?
That’s how far I got…
Thanks Grama for the title!