:+1: or `ko.func.operators`. 

Taking a second look, the `and` is not really equivalent to the && we are used to.
The signature of && is `Bool -> Bool -> Bool`, while ko.validators.and is `(a -> Bool) -> (a -> Bool) -> a -> Bool`
Should it still be called and (andF, applyAnd)? Or maybe put in another namespace that is not `operators`?