RinkWorks: Stupid Emails: Logi-Number Miscount

625. Logi-Number Miscount

To:  sam@rinkworks.com
Subject:  Your brainfood page
Date:  Fri, 15 Oct 2010 19:28:28 -0700

Folks,

I just went to your brainfood page and the logi-number puzzles. Either
the first puzzle or the instructions are in error. The instructions
say that the values of the variable must lie in the range of 1 to the
number of variables. The first puzzle has the variables A, B, C, and
E. Thus the values must be in the range [1, 4]. However, the square
grid is 5x5 and the hint is that A is 5.

Thus, you should say somewhere that it is not the variables in the
equations that count (the usual mathematical practice) but the size of
the puzzle grid and that the result should have exactly one green
light in each row and column of the grid which include variables not
explicitly used in the equations.

If you are going to try to help people sharpen their minds with
puzzles, please make sure the puzzles themselves are sharp.

In any case, thanks for this interesting page.

From:  Samuel Stoddard <sam@rinkworks.com>
Subject:  Re: Your brainfood page
Date:  Mon, 18 Oct 2010 10:12:20 -0400

That's because there is a variable D that goes unmentioned in the equations.
Its presence on the grid should have been a clue.

I was in a good mood. I should have slammed the guy for being such a passive-aggressive pedant.