The puzzle got edited, and unfortunately a crucial phrase got left out that invalidates these solutions.
Originally the puzzle said:
The lines can’t go through, along, or outside any of the boxes
A couple people, including me, mentioned that the very last part of the phrase (“can’t go… outside any of the boxes”) didn’t make any sense. But the first two clauses are crucial.
Unfortunately, @frauenfelder in his (good) haste to improve the instructions cut out that line, but the initial part of the rule is needed.
The rules should state:
Draw three, non-intersecting curved lines connecting 1-1, 2-2 and 3-3
The lines can’t go through or along any of the boxes
The lines can’t go beyond the bounds of the large rectangle enclosing the boxes
No, such a thing doesn’t exist as far as I know, but I’ve always wondered why not. In the winter the outside air is 10ºF, I heat my house to 62ºF, and then cool my freezer back down to 0ºF. In makes no sense. I just want a hole in my wall, with an insulated flap controlled by a thermosensor.