Nice tip. I've marked your comment as a spoiler (since it contains your solution).

FYI, comments (including ones that are posted in the solutions section of a kata) are exposed to everyone (including those who haven't solved the kata, yet) so it's best to mark anything containing spoilers with the Spoiler tag. This way, only those who have solved the kata will be able to view your comment.

You are right. Fixed.

Hey, that's really good to know; thank you!

Hmm, I see and you are correct. The test cases should cover this.

Unfortunately They are locked now and we cannot add them.

Don't forget to specify the constructor when changing the prototype.
Anyway, best solution for me because left the fullname property out of the constructor ;)

NamedOne.prototype = {
constructor:NamedOne,
(...)
}

When doing:

var addTwo = add(2);
console.log(addTwo == 2) //true
console.log(addTwo(3) == 5) //true
console.log(addTwo(3)(5).valueOf()) //13

The last line should return 10 instead of 13

Woul you mind elaborating a little?

How is this wrong?

Try same( [[1,5], [2,7]] , [[0,6], [2,7]] ) and you will see it's not a valid solution.