TGI... M/T/W?

I had a very exhausting weekend.

Saturday:

8-noon pack and move boxes of books, clothing, and some large furniture to new apartment (thanks to the heroic friends who turned up to help!); sprint to pool
noon-2 swim practice
2-5 more packing and moving, though slightly toned-down since by now I'm having trouble walking
5-8 go to Ikea, too tired to effectively find suitable windowshades
9 drop into bed already unconscious

Sunday:

8-3 unpack some things at new place, pack things at old place, move a little more; help roommate carry her boxes up the perilous fire escape into the apartment
3-5 another swim practice
6 drag myself to buy food, cook it, eat it, fall asleep

I was truly thankful for Monday to roll around, since it meant a reprieve from the gruelling swim practices. My new, noisier street has meant uneasy sleep (and strange dreams), and the first half of the week has flown by in a sore, tired daze. I wrote parts of this post on Sunday, intending to post it Monday, and you can see how that turned out. I need a break, but my bookshelf and several crates of books are lingering at my old place, and there's shopping to brace myself for this weekend.

Lots of projects and projectlets are moving forward; there's research and writing to do, games night #100 celebrations to plan, another teammate for the puzzle challenge to find, my parent's visit to anticipate, GHC (need to get cards, a finished résumé), my Canadian Thanksgiving trip, office hours and grading, ongoing knee therapy/care, and my birthday is Saturday. (Project Simplify update: I've sold two books online, posted several others, and assembled a pile of clothing to donate.) This is besides all the daily rituals and upkeep. I feel very busy. It will really help when I'm completely moved into the new apartment.


In the spirit of moving furniture, this post's theme word: antimacassar, "a small cloth placed over the backs or arms of chairs, or the head or cushions of a sofa, to prevent soiling of the permanent fabric."

Knights and knaves puzzle variations

My guess is that nearly all my readers have heard the basic knights/knaves puzzle, but I have recently come across interesting modifications of the problem. (It took four -- count them! -- theory grad students to figure out the "challenge" below, and it is probably within ε (i.e., nigh) of murderously frustrating for non-mathematical laypeople.) I have not solved the last three, although two of them have solutions posted on Wikipedia.

As so often occurs in puzzles, you find yourself shipwrecked on an island. The population of this island can be partitioned into two groups: knights and knaves. Knights answer all questions truthfully; knaves always lie. While wandering, you come upon a building with two doors, each guarded by one native islander. You know that one of the doors leads to a pile of treasure, and the other leads to a hungry, man-eating lion. You may ask a single yes/no question to one of the guards. Then you must select a door, and meet your fortune/death.

Warm-up: If you know that exactly one of the guards is a knave and one is a knight, what question do you ask? This is the standard knights and knaves puzzle.

Challenge: If you know nothing about the distribution of the two islanders (maybe two knights, maybe two knaves, maybe one of each), what question do you ask?

Hard challenge: The island also contains some residents who reply at random. You happen upon three islanders, and know that there is one of each type (Knave, Knight, Random). You may ask three yes/no questions. (Each question can be addressed to only one of the islanders.) What do you ask in order to determine their identities?

Harder challenge: Same as the hard challenge, except that the islanders reply in their language, where {yes, no} = {foo, bar} but the exact correlation is unknown. Wikipedia lists this as "the hardest logic puzzle ever."

Impossible:

This post's theme word: ambisinister, "clumsy with both hands." Unfortunately, it does not mean that you are equally sinister with both sides of your body.