[papertyger]

BTW, The answer is "yes" if the 'piece' of the puzzle you are talking about is the box containing all the pieces.

That is simply moving outside the terms of the analogy. The box is not a puzzle piece, and the last piece does complete the puzzle.

There is no reason to alter the terms other than attempting to avoid an unwanted conclusion.

[Chaguito]

And no analogy ever proved anything. And words mean things.