Given a list, if would be nice to have an equation function to format a list using natural language.

Potentially, this could be done by extending the `join()`

function such that if a deliminator isn’t specified it uses natural language.

For instance:

`join(["a", "b"])`

“a and b”

`join(["a"])`

“a”

`join(["a", "b", "c", "d])`

“a, b, c and d”