# Archive for December, 2013

## Listener 4270: Alma Mater by Oyler

Posted by Dave Hennings on 20 December 2013

A delayed mathematical due to Ilver’s wonderful Doctor Who last week. Hopefully there are no mathematical lovers who book their holidays to avoid the penultimate Saturday of every third month… or indeed mathematical haters who book their holidays to coincide!

This week was an Oyler puzzle with two-digit primes summing to 600. I don’t know why the preamble didn’t tell us that only eight were used here. They normally do things for a reason, and I’m guessing that it was to delay the realisation that the sum of the top eight primes is 620, and in fact there are only a limited number of combinations that sum to 600 — just three, I think:

– 97 + 89 + 83 + 79 + 73 + 71 + 67 + 41
– 97 + 89 + 83 + 79 + 71 + 67 + 61 + 53
– 97 + 89 + 83 + 73 + 71 + 67 + 61 + 59

The starting point turned out to be pretty easy, with the last digits of 23ac (S) and 15dn (AS) coinciding and meaning that both A and S must end in 1. From 20dn A^S, we have 71^61 which ends 71, 71^41 also ending 41, or 61^41 ending 61. Thus A is 71 or 61 and S is 61 or 41. 12dn AA is either 5041 or 3721 and 15dn AS is 4331 or 2911, but not 2501 which results in 18ac beginning with 0.

Another point worth noting is that an even number of additions/subtractions results in an even number, while an odd number will be odd. I noted this in the top right corner of such cells, eg 5ac T+E-A ends O for odd, while 13ac R+A+W+T+E+N is E for even.

After that, things went fairly quickly for me with the long down entries at 6 WANT + REDS, 8 DREW + STAN and 9 SWAT + NERD being the last to be slotted in. It was only as I was entering the last digits of these entries that I realised the hints that Oyler was giving us, especially DREW STAN which is STAN DREW the wrong way round. So a quick check of Wiki and I find that the University of St Andrews, Scotland’s first university, was founded in 1413, so that date went in at 1ac and 2013 at 31ac.

The values of each letter were A = 71, D = 79, E = 89, N = 73, R = 83, S = 41, T = 67 and W = 97.

The symmetrically hidden versions of the dates didn’t take long to find since it was a dead giveaway that the two lines would be the diagonals representing the white cross on the Scottish flag. I drew them in, but they were a bit of a puny version of the flag which the animation shows up better. (I forgot to take a copy of my submission, so no little insert this week.)

What a nice coincidence it was, not only that the 50th anniversary of Doctor Who appeared on a Saturday but that it could nudge the usual occupant of that penultimate Saturday to a 600th anniversary slot the following Saturday, St Andrew’s Day. Was it Ilver, Oyler or one of the editorial team. Whoever it was, it finished off a superb couple of puzzles, so thanks to all involved.

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## Alma Mater by Oyler

Posted by shirleycurran on 20 December 2013

“Alma Mater”, said the other Numpty. ” Quite a coïncidence as 2013 is the 600th anniversary of my first Alma Mater, St Andrew’s University.  Well, down to work. Let’s work out the frequency of those letters. Hmmm! Strange, there are only 8 letters used. D, T, E, A, W, R, S, N!”

I hadn’t yet retreated out of firing range (as I habitually do until the later stages of the numerical Listeners – which can be several days of bearish growling later) and a minute’s fiddling with those letters provoked some muttering: “More than a coïncidence here. St Andrew’s! 1413 to 2013! This Saturday is also St Andrew’s day. Well done, Oyler! Preamble understood, perhaps? Do you suppose we put those two dates into 1ac and 31ac? That seems more than likely, and 1d can only be 1xx, so 1ac is 1413 and, 31ac is 2013. Progress! And the thematic shape must be a saltire, roughly corners to corners, passing centres of squares containing 1,4,1,3 and 2,0,1,3.” (Three minutes into a numerical Listener and the theme sussed – that has to be our record!)

Arithmetic might now be needed. A list of prime numbers is opened and there are only 21 from 11 to 97. Eight have to add up to 600 to thematically commemorate that anniversary. Some clues are numbers like perhaps 73^71. Awkward. I doubt that we have the calculator or device to work that out, but since Oyler is apparently a St Andrews man it’s probably not necessary to do a lot of maths, just find a  shortcut to get the last digit …..

To sum to 600, these 8 2-digit primes  are likely to be the forms x1, x1, x3, x3, x7, x7, x9 and x9, so the 8  tens parts need to add to 580. No 1x is possible, as  the maximum  for the 7 others is 559. Neither is 2x or 3x. That leaves only 13 primes to choose from ranging from 41 to 97. Looking at 18ac, 600+D-W-2E, this can only start with 6, 5, 4 or 3 so A can only be 71 or 79. Guess 71? From 23ac,  S, and 15d, AS, needing a common last digit, S must end in 1, so is 41 or 61. So is Oyler being kind, with S,T,A,N,D,R,E,W in increasing order, as 41, 67, 71, 73, 79, 83, 89, 97? Looks good! Digits interlock! Even the splendid WANT+REDS, DREW+STAN and SWAT+NERD fall into place.

What about 10ac, N^A or 73^71, and its friends, 2d, 3d and 20d, the giant numbers? No problem really, as  73*73 ends in 9. So 73^4 ends in 1, as does 73^68. So 10ac ends in last digit of 73*73*73 or 7. The others can be handled similarly. What an ingenious and pleasant puzzle, no computer needed, only fingers! I admit that the literary Numpty spotted the saltire-defining  squares first, though.

It had to be he saltire didn’t it – especially considering the shape of the grid (unlike that Swiss flag we had a few years back, that used one of the very rare square flag shapes). It was obviously a matter of searching along the diagonals, and, sure enough, there on the 1st, 3rd, 7th and 10th were the culprits. Saltire it is! Thank you Oyler for our speediest and most enjoyable numerical Listener ever!

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## Journey to the Centre by Ilver

Posted by shirleycurran on 13 December 2013

There was an immense whoop of relief from at least one Numpty when we realized that a numerical Listener was not being inflicted upon us this week (or was it? All those little numbers scattered around the grid had us wondering!)

Of course, we have been saying, all week, that with so many anniversaries this weekend, (the Gettysburg address, the Kennedy assassination, Benjamin Britten’s centenary and the fiftieth anniversary of some weirdo scientific fellow who flew through time and space in a police phone box) the editors would be mad to give us a numerical. What good sense to step out of the straitjacket and honour or commemorate at least one of those!

The preamble told us fairly clearly which of those we were celebrating but we were a long and winding road from our destination in this journey to the centre. At first, this involved cold-solving, and we are never very good at that. The only gift was that, when we had a few clues solved, and some were generous, we had the length, first and last letters of the adjacent ones. However, the ‘winding’ aspect of the journeys flummoxed us in a few cases – even my very last clue, where I needed to insert EMOTED in order to get to the centre, but had already placed the I of SLID in the second E cell – so easy to go wrong. It was fun though!

Fun? As usual, I gave a speedy troll through the clues to check that Ilver was still a member of the Listener Setters’ Imbibing Association and he just qualified, with his ‘Fermented juice on French afternoon (4)’ SUR + A and, later on, ‘Research frothy ale and decide again (6)’ RES + ALE* giving RESEAL. I have seen him being far more discerning about his choice of beverage (well, we are part of a team of setters) but I imagine, on this occasion, the need to find an O in the fifteenth of his 26 left-over clues made him descend the path of choosing ale with far too big a head on it. Such is the downside of compiling!

In truth, with that constraint, his clues were of the usual high Ilver standing and, for once, generous on the whole so our grid was filled after a few hours of flailing, with the task becoming far easier when only the fourth journey was left to complete and a number of cells were left vacant, clearly indicating the route.  What’s more, the message hidden in the first 34 clues was emerging: COUNT A LETTER IN EACH OF REMAINING CLUES.

OK, time for a confession. Rather a long time ago, we test-solved this puzzle. Friends say to me ‘No doubt you have done this already and you’ll be sitting like a Cheshire cat watching us struggle’. Well, this is perhaps the place to disillusion them. First about a test-solve: there is often an immense difference between the original creation and the one that goes off to the Editors. There is then another time-shift to the polished product that appears one, two or even five years later. So what changed? Well, that instruction about how to complete this was nowhere near so clear in the original version (and there was a miscount in how many sides of one of the letters had to be adjacently coloured) and I thought it might be amusing to insert here what I produced on my first attempt to suss out what was going on. It is perhaps better to relegate that one to the bin!

I had realized that there were 26 remaining clues and that I needed to count the frequency, for example, of G in the G clue,  or Y in the Y clue and somehow apply that to the letters in the grid, but even that led to more than the usual Numpty head scratch.

Secondly, clues change, too becoming, on the whole, far easier, and this time, the changes made a slight difference to the instruction. Anyone who thinks ‘The Editors must have made a mistake’ (as I occasionally hear) needs to submit a crossword and experience the detailed to-and-fro dealings of compiler and editors that produce what we finally see.  All that to say that vetters and test-solvers – and there are two or three, probably, for almost every submission before it even reaches the Editors, are not really being privileged to get an early glance – they have to re-solve anyway when the puzzle appears.

Back to the point! Fortunately, once the penny had dropped and I realized that some graphic depiction of the Tardis was not going to emerge from the grid, I was able to be a little more rational in my shading of letters, beginning with those around that centre cell. The device became clear, as did DOCTOR WHO.

What was left to do? We needed to understand how putting an L in the centre cell to reflect the fiftieth anniversary was ‘thus completing a representation of the transport in that row’.  All setters have to occasionally resort to that crosswordese use of EM and EN as ‘spaces’ and there was EM surrounding T and REL DIM. That, it seems, says ‘Time and relative dimension in space’ which gives TARDIS (Wow!). Dare I admit, that I don’t know much about the Doctor Who series but I’m happy to go with that.

Criticism, though. We are going to watch the fiftieth anniversary special broadcast this evening and we are looking forward to those anguished elephant trumpeting noises that accompanied every movement of the Tardis. Ilver has missed the chance to require a recorded message as his final endgame. ‘Solvers must send JEG  a recording of a relevant sound accompaniment to demonstrate that they have found a way out.’

What is left to do? Congratulate Ilver on an astonishing compilation. I have seen what must be hundreds of hours of work that have gone into that polished production. Quite something!

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## Listener 4269: Journey to the Centre by Ilver

Posted by Dave Hennings on 13 December 2013

SCENE: The Editor’s office early in 2013. There is a desk in the centre of the room. There are two chairs either side of the desk, a big one and a small one. Editor sits in the big chair, Sub-editor sits in the smaller one with a laptop. Editor puts a piece of paper on the desk. The piece of paper has a crossword puzzle printed on it.

Editor: Well that’s 16th November sorted. What have we got available for the 23rd? It’s the last mathematical of the year.

Sub-editor: Hmmm… why does that date ring a distant bell. Let me google “Anniversaries November 2013”

Sub-editor types furiously on his keyboard.

Sub-Editor (reading off screen): “The first episode of the science fiction television series ‘Doctor Who’ was broadcast in the UK. It is the longest-running and most successful science fiction TV series in the world.” Well, we could commission a special mathematical around the equation of space-time and the twelve dimensions. Elap could write a computer program to work out the interspatial vertices.

Editor: OK, I’ll send him an email tomorrow.

Sub-editor: What are those two envelopes doing in the in-tray?

Editor: That’s odd… I didn’t think we had an in-tray.

Editor takes the two envelopes out of the in-tray and opens the first one.

Editor: It’s a mathematical puzzle from Oyler.

Sub-editor: Well that’s lucky. What does he have to say?

Editor (reading a letter): He says it’s the 600th anniversary of the founding of the University of St Andrew’s, this year and he’s enclosing a puzzle he’s done to celebrate it. He’s also suggesting that publishing it on 30th November would be good as that’s St Andrew’s Day.

Sub-editor: That wouldn’t work… everyone’s just got used to the mathematical moving to the penultimate Saturday of every third month.

Editor: You’re right. I’ll reply that it would be too confusing.

Sub-editor: What’s in the other envelope?

Editor: It’s a puzzle from Ilver. He says it’s the 50th anniversary of Doctor Who on 23rd November this year and he’s enclosing a puzzle to celebrate it. (He pauses.) Oh well, it looks like we’re destined to confuse everyone. I’ll schedule them for the dates they’ve suggested. Sorted!

Sub-editor: Where’s the in-tray gone?

###### Any similarity to actual events is in the realms of science fiction.

Fast forward to November 2013.

Well, they weren’t going to surprise me this week… I was ready for the quarterly mathematical puzzle. It was just a shame that it fell on 23rd November, the date of the anniversary of Doctor Who that the BBC had been flagging for most of the year! Never mind, I got to blog Stick Insect’s EV puzzle, Distortion, and Nimrod’s IQ, combining the 50th anniversary of JFK’s assassination the day before.

Upon opening the paper, I had the same sort of feeling as I did with Mr Magoo’s domino puzzle, except that had a grid that seemed too small for a normal puzzle and here it seemed too big for a mathematical. A quick read of the preamble, ending as it did “thus completing a representation of the transport in that row”, and I realised we were indeed in Doctor Who country, the transport being the TARDIS.

The unfortunate thing was that I probably had a lot of cold solving in front of me. Moreover, certain clues (as seems common these days, we weren’t told how many) had an extra wordplay letter, but they shouldn’t be too daunting.

Luckily, the clues, all good, were pretty straightforward, but it took me about an hour to finish my first pass through them. Not that that bothered me… I had solved over 40 of them, and the grid was coming along nicely. I’d even managed to get the message spelt out by the extra letters: Count a letter in each of remaining clues. All that was in the first run of clues, with the rest not having any extra letter at all. How wonderfully sneaky! Moreover, the clues without an extra letter numbered 26, so it was obvious that something needed to be done with them, one for each letter of the alphabet.

It wasn’t much later that I had a full grid, and the instruction had to be interpreted. My initial thought was that we had to count the occurences of each letter of the alphabet in the clues in order. Unfortunately, the F in row 2 column 1, had to be surrounded by four shaded cells and that conflicted with the W in the top left corner which would be surrounded by none.

I tried various other possible interpretations, including trying to find one particular letter whose appearance in each clue indicated how many shaded squares there were. Nothing worked out.

It wasn’t too long before I checked my four word chains and discovered that I hadn’t finished the top left corner correctly. Indeed, the end of stage 6, REALTER didn’t appear properly at all. Stupid boy! My first instinct about counting each letter of the alphabet in order proved correct, and I built a new grid containing the numbers 0 – 4 and corresponding to the number of shaded squares that should surround each one.

This stage proved a little bit tricky, but was very rewarding when it all worked out correctly, and there in front of me in large letters was DOCTOR WHO. Obviously L, for 50, needed to be slotted in the central square to reveal ETRELDIMM, ie T (time) & REL (relative) DIM (dimension) in EM (space), which is what TARDIS stands for.

Thanks, Ilver, for a superb (and not too tricky) implementation of a wonderful anniversary.

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## Listener 4268: Check This Out by Charybdis

Posted by Dave Hennings on 6 December 2013

It was over two years since Charybdis’s last Listener, with its graph reflecting the exponential growth in the human population. Here we had 1 across being part of a simile from a novel, with the author to be highlighted in the grid. Presumably the simile wasn’t in the ODQ, since we were told exactly where to look for it… near the beginning of the author’s second novel.

Bizarrely, surprises were in store! But we weren’t told the nature of the surprises. Also, there were two groups of clues, but we weren’t told how they differed. Finally, there were ten unclued entries that were thematically related. Thanks for confusing me, Charybdis.

There was only one thing to do, and that was to solve a few clues. Luckily, when I came to 30ac Pair of horses dead in Senegal (4), things became clear (I hoped). Senegal is SN and a pair of horses is a SPAN, so it’s PA in SN, and ‘dead’ should read ‘dad’. The Group I clues looked as though they might have an extra letter. It made me wonder why we are ever told about extra/missing letters or misprints if Charybdis can get away with mentioning it so obliquely!

43ac Estate initially provided with altered dates and places (6) led to STEADS with ‘Estate’ needing to lose its first E so that it was the initial letter of State that took DATES*. So that was just two Group I acrosses dealt with, and sadly, I only got two Group I down answers in my first pass: 22 SCRAG-END, being SCR + AGEND[a], and 39 LADS.

What would the Group II clues hold? I assumed that it would be a different surprise, and the first clue, 38ac Aussie youth without grace backed into brigadier (3) was DAG, but had to go in a 4-letter entry. In fact, a quick check revealed that all the Group II clues led to answers one letter shorter than their entry. How nice of Charybdis to make life a bit easier here and give us answer lengths.

The Group II clues were much easier than Group I, and I got most of them fairly quickly. Presumably they would be need to have a letter added to give the entry, and that would no doubt be a real word.

Back to the Group I clues, and despite knowing there was an extra letter in every clue, some were quite tricky little blighters. Getting 26dn MONDIAL (‘ruing’ having a redundant G) enabled me to get 47ac Peers riot with leadership on vacation and earldoms in ruins (13, two words), LORDS TEMPORAL. It took me some time to be sure of this, since the wordplay of (ROT (‘riot’ without the I) + LP (LeadershiP on vacation, ie empty) + EARLDOMS)* wasn’t particularly straightforward, at least for me. It was a pity that this wasn’t 1ac as that would have helped me work down from the top of the grid.

No, sadly 1ac was the unclued key word, and it was some time later that INCONSPICUOUS could be seen struggling to appear. Even more sadly, absolutely nothing came to my mind as being ‘as inconspicuous as’ anything at all. This meant that the grid had to be completed before RAYMOND CHANDLER could be seen in columns 1 and 12. Google provided the title of his second novel, Farewell My Lovely with Philip Marlowe the hero.

Using the unchecked letters given in the preamble, I was already happy that the ten unclued entries were items of food and drink. The extra clue letters spelt out Unexpected item in bagging area, and the letters that needed to be added to the Group II answers spelt out Remove item. Little did I think that I would end up in my local supermarket, but I quickly scanned the grid (no pun intended) to see if any obvious item stood out. However, I didn’t really know what I was looking for, so missed the offending creature! I ended up at an obscure Ukrainian site, www.ae-lib.org.ua, which provided “Even on Central Avenue, not the quietest dressed street in the world, he looked about as inconspicuous as a tarantula on a slice of angel food.”

Removing the tarantula that was now obvious in column 5, I saw that angel food (presumably the same as angel-cake in the UK) was lurking under the sneaky arachnid. At least it would appear when I completed my final submission grid. Or should I say that it would appear if I remembered to replace the TARANTULA with ANGEL FOOD on my final submission grid. I was, in fact, half way through creating that grid when I realised I was in the process of sending the spider off to St Albans!

So, a lucky escape at the end of an entertaining puzzle that brought together two seemingly disparate ideas. Thanks, Charybdis.