Please improve these comprehensions (was meaning of [ ])

[Ian Kelly]

On Wed, Sep 6, 2017 at 1:37 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
>
> Which reminds me of this puzzle I saw a couple of days ago:
>
>    1 + 4 = 5
>    2 + 5 = 12
>    3 + 6 = 21
>    8 + 11 = ?
>
> A mathematician immediately comes up with a "wrong" answer.

There are no "wrong" answers with these kinds of puzzles. There are
only answers with varying degrees of parsimony with the known facts.

I say the answer is clearly "banana" because the key to the puzzle is
that everything matches a line from the following look-up table:

5 => 5
7 => 12
9 => 21
19 => banana