[kovrik]

> In math ( * ) is a binary operation.

https://en.wikipedia.org/wiki/Empty_product

I am talking about Empty Product.

In all Lisps I know ( * ) returns 1, (* n) returns n. Which makes sense.

Shen's example is confusing for me.

[MichaelBurge]

* :: a -> a -> a

Π :: {a} -> a