One more comment on “canonical,” promoted to its own post because the non-mathematicians presumably stopped reading the other one very early on.
It’s common for mathematicians to use the word “canonical” colloquially, to mean something like “a choice universally or at least generally agreed on.” For instance:
The clock in Grand Central Station is the canonical place to rendezvous with people in midtown New York City.
I always thought of this as an outgrowth of the mathematical use of the word; but actually, there’s a bit of tension, because I think in this sense “canonical” almost always refers to a choice which is conventionally agreed on, and for which there might be a good reason, but which isn’t really forced upon you the way that canonical things are in mathematics. The canonical rendezvous might just as well have been the lobby of the Empire State building.
I found a definition of “canonical” in a Hacker Slang dictionary which roughly agrees with this usage:
The usual or standard state or manner of something. This word has a somewhat more technical meaning in mathematics. Two formulas such as 9 + x and x + 9 are said to be equivalent because they mean the same thing, but the second one is in `canonical form’ because it is written in the usual way, with the highest power of x first. Usually there are fixed rules you can use to decide whether something is in canonical form. The jargon meaning, a relaxation of the technical meaning, acquired its present loading in computer-science culture largely through its prominence in Alonzo Church’s work in computation theory and mathematical logic (see Knights of the Lambda Calculus). Compare vanilla…
Anyway. Non-math readers, would you ever use the word “canonical” in the sense described here? Math readers, can you give an account of its colloquial usage more articulate than my own?