| Title: | Mathematics at DEC | 
| Moderator: | RUSURE::EDP | 
| Created: | Mon Feb 03 1986 | 
| Last Modified: | Fri Jun 06 1997 | 
| Last Successful Update: | Fri Jun 06 1997 | 
| Number of topics: | 2083 | 
| Total number of notes: | 14613 | 
Many of us are familiar with the word-shift puzzle associated with the
movie in 2001.  Namely, add 1 to each letter of the "HAL", the name of
the computer in the movie, and you get "IBM".
In a mathematical sense, we can represent this fact like this:
	IBM = HAL + 1
I ran a procedure on our computer to search the on-line dictionary for examples
of sets of English words that are related by shifting letters.  The longest
words that work are:
	SULPHUR = PRIMERO + 3
Here are others I liked.
	NOON = DEED + 10
	RUT = ILK + 9 = BED + 16
	LOO = ILL + 3 = BEE + 8 = ADD + 11
	ILLY = BEER + 7
	LOX = FIR + 6
	FIX = BET + 4		(Something about fixing a race ?)
	FROG = COLD + 3
	HUSH = BOMB + 6		(Sort of a gruesome association)
	ONYX = BALK + 13
	SPUR = LINK + 7		(Isn't there some mountain in New England
				 containing two trails with these respective
				 names ?)
	ROUT = LION + 6
	HERO = DANK + 4
	OWL = GOD + 8		(Hey Topher, Toby, you read me ?)
	STOP = HIDE + 11
	JERK = FANG + 4
	LOOP = BEEF + 10
	INGOT = CHAIN + 6
	PEPPER = LALLAN + 4	(I hope LALLAN is a word.  I don't know what
				 it means)
	SEX = OAT + 4		(I liked this because of the "sow your
				 wild oats" loose connection between the words)
	TIGER = PECAN + 4
	JOLLY = CHEER + 7	(My favorite)
	VEX = RAT + 4
	WET = SAP + 4
	SURE = PROB + 3		(Kind of cute, given the meaning of
				 "probably" vs "definitely")
	SUING = MOCHA + 6
	TIE = PEA + 4
	PET = LAP + 4		(Something about a lap dog ?)
	TWIN = LOAF + 8
	STIR = OPEN + 4		(two words from a recipe ?)
	ZOO = PEE + 10 = ADD + 25	(wrap around from Z to A again)
	SHOW = PELT + 3
	TWO = RUM + 2 = LOG + 8
p.s.
   In case you're wondering how my computer procedure worked, the
   main steps were:
   1) Run a program that takes every word in the dictionary, subtracts
      whatever it needs from every letter such that the smallest letter
      becomes "A", then outputs both versions as a record.  So JOLLY
      and CHEER will appear in the list as
	AFCCP                                  CHEER
	. . .
	AFCCP                                  JOLLY
   2) Use the dcl SORT command to sort the records.  This causes all the
      ". . ." lines to move elsewhere, bringing the "CHEER" and "JOLLY" records
      together in the file.
   3) Run a program that scans the sorted file and prints out all sets
      of consecutive records that have the same left-hand column.  Hence
      since "CHEER" and "JOLLY" both have "AFCCP" in their left-hand
      column, they get printed out.
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 234.1 | HARE::STAN | Fri Mar 08 1985 15:01 | 3 | ||
| net.map on USENET had a recent posting asking what English words were transformed into other English words by the UNIX rot13 algorithm (i.e. WORD1+13=WORD2). | |||||
| 234.2 | SPRITE::OSMAN | Fri Mar 08 1985 17:10 | 57 | ||
| Whoops !  Due to a bug in my algorithm, my procedure missed a bunch.
I discovered this because a few weeks ago I published a study of those
words whose "difference" is 13, a study motivated by the common practice
within USENET news files of "rot13"ing potentially offensive material.
At that time, the largest example discovered was
	NOWHERE = ABJURER + 13
I happened to notice just now that this example was missing from my
original list.
The bug was that I shouldn't have subtracted whatever makes the
SMALLEST letter be "a".  I should subtract whatever makes the FIRST
letter be "a".
Anyway, having fixed the problem, I can now offer the following:
	KNEE = FIZZ + 5
	GNARL = XERIC + 9	(I haven't looked up XERIC, but assuming it's
				 a word, I like this one because it has my name
				 in it.)
	SATIN = MUNCH + 6
	IRON = FOLK + 3
	TEAR = PAWN + 4
	GROG = WHEW + 10
	GROW = DOLT + 3		("All DOLTS ought to GROW up 3 years !")
	SHALE = LATEX + 7
	LAYOUT = FUSION + 6
	APTLY = TIMER + 7
	ARENA = RIVER + 9
	NEST = HYMN + 6
	ASS = WOO + 4		(I better not say anything about this one)
	BUNNY = SLEEP + 9	(Nor this one)
	PIES = HAWK + 8
	BURY = SLIP + 9
	HAZER = BUTYL + 6
	KEG = ICE + 1		(nice association: icy cold keg of beer)
	FAGOT = TOUCH + 12	(hmmm)
 | |||||
| 234.3 | HARE::STAN | Fri Mar 08 1985 17:29 | 3 | ||
| Correction to .1: "net.map" should read "net.math". Sorry. [Response .2 came in before I had a chance to correct this typo.] | |||||
| 234.4 | TURTLE::GILBERT | Fri Mar 08 1985 18:19 | 14 | ||
| Re .2 This doesn't sound like a bug to me -- you should end up with the same results either way. Consider the simple case of IBM and HAL. With the first method you'd get: HAL HAL HAL IBM With the second method you'd get: A:E HAL A:E IBM In either case, these still map 'together', and would be recognized as word-shifts of each other by the final pass. | |||||
| 234.5 | SPRITE::OSMAN | Mon Mar 11 1985 10:04 | 9 | ||
| Yes, it was indeed a bug ! If you use my original algorithm, you miss the gem NOWHERE = ABJURER + 13 Now I leave it to you to describe the characteristics of the set of words that the bug leaves out. (The bug being normalizing to smallest letter instead of first letter) | |||||
| 234.6 | TURTLE::GILBERT | Mon Mar 11 1985 11:27 | 1 | ||
| Ah! Wrap-around. Z + 2 = B. | |||||
| 234.7 | METOO::YARBROUGH | Mon Mar 11 1985 11:29 | 1 | ||
| You still have a bug. Else how did you get ZOO = ADD + 25? | |||||
| 234.8 | SPRITE::OSMAN | Tue Mar 12 1985 10:06 | 26 | ||
| Uh . . . . . . er . . . . . . Oh ! It should be "ODD" instead of "ADD". My mistake. sorry :( | |||||
| 234.9 | WNT = VMS + 1 | HERON::BUCHANAN | The was not found. | Tue Mar 30 1993 05:16 | 0 |