In The Language of Mathematics: The Stories behind the ... You describe Gerhard Gentzen’s “for all” symbol (∀) as a “cubist tear flowing from an eye that Picasso could have painted.” ...

In fact, he describes the current state of the symbol in his paper using a key ... we can do it pretty much without thinking at all. But math is an abstract field of study, and computer ...

Say you've got four 4s—4 4 4 4—and you're allowed to place any normal math symbols around them ... you can make all of them. Really. You just have to have some fun and get creative.