## QQF/U: Coins, Coin Purses, and Banks

This is a follow up to my investigation into Julia's helpful, but slightly idiosyncratic, ways of condensing down tuples.

Having evocative language for things is helpful. So I'm going to introduce the terms I've used since writing that post mentally to describe nested empty tuples and the ways they get condensed down.

- A
`()`

is a*coin*, same as in Haskell. - A
`( (), )`

is a*coin purse*, because it holds coins. - A
`( ( (), ), )`

is a*bank*, because it holds coin purses.

When Julia does the syntactic-sugar thing where `((())) == (()) == ()`

, we call that *robbed*. So:

- A
`((()))`

typed at the REPL is a*robbed bank*, - A
`(())`

typed at the REPL is a*robbed coin purse*.

I'll leave it to your imaginations to generalize these further. ðŸ˜‰