corollary

Wednesday, 1 February 2012

Board Games IIa

Listening to:

Shostakovich, symphony no. 7 in C major, op. 60 ‘Leningrad’. Played by the St. Petersburg Philharmonic Orchestra, conducted by Vladimir Ashkenazy.

Some Games Played Last Year

Here are some board games I played last year, mostly on Monday nights. The associated comments are miniature reviews, if you like, but reviews derived from only a small number of plays in most cases.

7 Wonders

A “builder”, where the thing being built is a rather abstract representation of a civilisation. You can focus on resources, or science, or the military or just awesome buildings. It has minimal random elements, but can still feel rather random in the way it develops, thanks to the fact that people are playing simultaneously from hands of cards that are whittled away. This central mechanic of playing cards from hands that are shared around the table is definitely cool. The multiple routes to victory work well. I don’t really feel in control when playing though, and that feeling of detachment is not ideal.

Acquire

An oldy but a goody. A cute representation of capitalist investment in corporations, where the only objective is to own big companies, and to be the beneficiary of mergers that you and other players bring about. It has just enough fidelity to what I imagine the real world might feel like to be fun, but it’s clearly silly in a number of ways. Has been fun each time I’ve played it (have managed it perhaps 3 times in total). It’s definitely too slow to finish, and there is too much luck in the draw of tiles. It hasn’t happened to me, but it’s easy to see how the game might end up leaving you with very little to do each turn. This is due to the way money only flows in big bursts, and rather selectively. A better simulation might see money flow to and between players more evenly and more frequently.

Bohnanza

A fun, very social game where people are constantly talking and interacting with each other to hatch deals. I’ve played this one quite a bit, and I think it’s always been well-received when people first play it. The art on the cards is comically appealing, conveying the game’s essential light tone very well. I don’t know that one’s wheeling and dealing can ever be in the service of a long-term strategy. Instead, it’s all very short-termist (very tactical if you like). One’s skills are deployed to make the best of the current situation, and that’s definitely fun (if you like the wheeling and dealing), but I’ve never felt that I’ve been pursuing any larger vision.

Chicago Express

Another economic game, featuring joint (multi-player) investments in companies. It plays quite quickly, and has a very nice physical realisation (lots of cute wooden train bits that get deployed across an appealing map of north-eastern USA). I bought this mostly on the strength of the gushing comments on the BGG site (linked above), and I think I can see the same things in the game that the gushers wax lyrical about. There’s also a fine version of the game available for iOS devices (called Wabash Cannonball there). Unfortunately, people I’ve exposed this to have mostly been pretty unexcited about it. Some didn’t like the nastiness of buying into a company and then messing it up; another didn’t like the primacy of the auction mechanic (how shares are acquired), still another didn’t like having to share “their” successful company with another investor, even if that second investor was happy just to receive the dividends and keep the company successful.

More in this vein next time. Of the four above, CE has definitely been least successful. Unfortunately, of these four, it’d probably be my first choice. If I wasn’t allowed to play it though, I’d then go for 7 Wonders: it plays very quickly, still feels new to me, and may yet reveal hidden depths.

Wednesday, 8 February 2012

Dr. Tatiana’s Sex Advice to All Creation

Listening to:

transitions by Chris Jarrett, from the album Fire.

Just read:

Dr. Tatiana’s Sex Advice to All Creation, by Olivia Judson.

This is an entertaining book, full of little essays about the sex lives of various species. The basic conceit is that every essay begins with an “agony aunt” style question. For example:

Dear Dr. Tatiana,

I’m a true armyworm moth, and I’ve gone deaf in one ear. I’ve read this is from having too much sex. Trouble is, I’m (sob) still a virgin. So what’s happening to me?—Piqued in Darien

This particular question leads into a very nice discussion of why most species maintain a 50-50 male-female sex ratio, but why in certain (often parasitical) circumstances the ratio may dramatically favour females, at least initially. Even cooler, certain parasites can control the sexes of their offspring to suit the specific circumstances they’re in (whether or not they’re competing with other individuals, basically).

Given introductions such as the above, there’s naturally a fair bit of humour in the presentation of this material, but it’s also done very carefully. Olivia Judson is a scientist (multiple Nature papers according to the page about her on Wikipedia; cor!) as well as a science writer, and she clearly wants to makes sure that what she writes is properly supported by the evidence.

Definitely a recommended read. The bitty structure means there’s no grand thesis, but it still conveys a lot of absolutely fascinating material.

Wednesday, 15 February 2012

Abstract Algebra in HOL4

Listening to:

Mahler, symphony no. 1, “Titan”; Royal Concertgebouw Orchestra, conducted by Leonard Bernstein.

By algebra I mean stuff like group theory. This has always been difficult in HOL, mostly because of the relative inexpressiveness of its simple type theory. In particular, there’s no good way to set up a type of all possible groups, which is the natural thing to want. The best thing possible would be to get a type of groups over a parameter corresponding to the type of the carrier set. In other words, you could set up a type operator group of arity one, so that the type α group would be the set of all possible groups with carrier sets that have elements from the type α.

The funny thing is that most people don't seem to do this. Instead, they work with what you might call a pre-group. Such a thing might be a triple of carrier set, group operation, and group identity. Not all such triples are really groups because the required group axioms may not be satisfied.

The standard approach is to then define a predicate isGroup over the pre-groups. Then isGroup(pg) is true when the pre-group pg does satisfy the appropriate group axioms. You might then manage to prove a bunch of theorems of the form

  ⊢ isGroup(g) ∧ xg.carrier ⟹ g.plus g.identity x = x

You can do a whole lot of group theory this way, but just about every theorem you ever prove is going to have a isGroup pre-condition of some form. The experiment I want to perform is taking the subset of pre-groups corresponding to those triples that really are groups, and to then define a genuine HOL type on that basis.

You might still get theorems that require elements to be members of the underlying carrier set, but it’d still be an improvement, I reckon. Nor can I really see a possible down-side, at least as far as groups are concerned.

The only fiddle necessary is when you move on to rings and fields where the algebraic structure is usually understood to contain at least two elements (the zero and the one). You can’t then construct such a structure uniformly for all possible carrier types in HOL, because types may only contain one element. There are two possible work-arounds:

  • Make the carrier type actually be α option or some such, so that you can be sure that the type really is always big enough. This is pretty ick really.
  • Allow rings and fields to have zeroes and ones that are the same. I don’t know at this point how much violence this would do to the general theory.

Better yet, I have a potential student ready to start doing just this experiment, so I may be able to report back shortly.

Wednesday, 22 February 2012

Board Games IIb

Listening to:

Mendelssohn, Fair Melusina overture. Played by the Bern Symphony Orchestra, conducted by Peter Maag.

More Capsule Reviews of Board Games

For super-reduced reviews of games from our Monday Games Night, see Alban’s page.

Alhambra

Another so-called “gateway game”, perfect for introducing non-gamers to the hobby. It’s certainly pretty light, with simple mechanics, including an appealing tile-laying aspect. One is definitely at the mercy of a shuffled deck of money cards, and if playing with too many players (more than 3 or 4), it really does become impossible to plan because the revealed set of tiles that one purchases will change too much between one turn and the next. Not currently something I’d call to play myself, but I don’t actively dislike it.

Citadels

This game features a distinctive central mechanic, where each round sees you select a rôle from a set of cards, and then pass the remaining set onto your left for your neighbours to draw from. The psychology of judging what to take given what you expect others to take, and what you expect your predecessors to have taken, makes for a memorable game. I’ve mostly enjoyed my games of this, but it can drag something rotten if the card selections take too long. The rôle draws are done to build up a collection of victory-point-bearing city cards. These city cards are displayed face up on the table in front of you.

It’s possible to be badly victimised, though in a random way (people with the appropriate rôles pick their victims not by player identity, but by rôle, and so they can’t be sure who they will be harming). I don’t mind this much, but others have found this annoyingly frustrating.

Container

An economic simulation that I find very appealing. I’ve played it a few times, and always found it enjoyable, even if my strategic thinking has been completely superficial. For the moment, I’ve just been happy to sit back and think, Yes, there’s definitely an economic web happening here. The better player would then also figure out how to exploit that web in a reasonably long-term way. The flow of money, and the control given to the players make this a better economic game than Acquire, even if the turn-to-turn activity is pretty prosaic (production of wooden “containers”, the setting of prices, and occasional auctions).

Dominion

An extremely famous recent game, one that introduced the notion of “deck-building”. I’ve only played four times to date, but have enjoyed each experience so far. It’s pretty dry in terms of theme, but the mechanic is an appealing one to get one’s head around.

Wednesday, 29 February 2012

Lady Oracle

Listening to:

Handel’s Il Pastor fido: Hunting scene - March: Airs pour les chasseurs I & II

Just read:

Margaret Atwood, Lady Oracle.

This is an entertaining, though rather slight, novel about a woman who leads an eventful life, culminating in the faking of her own death. This is not a spoiler, because she narrates the novel and tells you exactly this in the novel’s very first paragraph.

The bulk of the novel is “flashback”: letting the reader in on the course of events that led to this sorry state of affairs. The story of the woman’s life starts with early childhood in Toronto, and the girl’s dysfunctional relationship with her mother. This stuff is all very vivid, as coming-of-age stories often are I suppose.

The woman’s teenage years and early adulthood are also compelling, what with it being all about escaping the parental nest, having her first love affairs and discovering her life skills.

The novel slowly shifts gears from this point, with the narrator’s relationship with her husband coming to the fore. Though there are still occasional moments of humour, it’s not as entertaining as it had been earlier. The woman gets all angsty, and the eventual crisis that prompts the death-faking seems pretty unbelievable.

I read the bulk of this while on a plane from Canberra to Sydney, and then on a bus doing the opposite journey. I enjoyed it, but I reckoned it ended weakly, and I’m not sure I’d give it much more than 6½ or 7 out of 10.