The case of the $2,000,000 comma and the ambiguous adjunct

Check it out — a comma in a contract is costing a Canadian communications company $2,000,000! A Basic Rule of Punctuation.

The long and the short of it is that Rogers Communications had a deal with another company, Aliant, Inc, who had agreed to string cable across utility poles in Eastern Canada for a fixed rate per pole. Rogers understood their contract (and per-pole price) to be in place for five years, and to be subject to renewal after that. Aliant Inc disagreed. They understood the contract to allow them to cancel at any time, with one year's notice. (After cancelling, they could then renegotiate the rate.)

The court case hinges on whether the the phrase about cancellation with one year's notice takes scope over the entire sentence about the duration of the contract, or (as Rogers thought) only the second conjunct of that sentence. Here's the crucial sentence (as excerpted in the Globe and Mail):

The agreement “shall continue in force for a period of five years from the date it is made, and thereafter for successive five year terms, unless and until terminated by one year prior notice in writing by either party."

So the issue is whether the constituent structure of this coordinated sentence is as indicated in (1) or (2) below. Rogers would have it that it's (1); Aliant is arguing that the placement of the bolded comma indicates unambiguously that it's (2):

(1) [ [ The agreement shall continue in force for a period of five years from the date it is made] and [[ thereafter for successive five year terms] [unless and until terminated by one year prior notice in writing by either party]] ].

(2) [ [[ The agreement shall continue in force for a period of five years from the date it is made] and [ thereafter for successive five year terms]] [unless and until terminated by one year prior notice in writing by either party] ].

Rogers, naturally, argues that the intent of the deal was understood by all at the time of its making:

Rogers was dumbfounded. The company said it never would have signed a contract to use roughly 91,000 utility poles that could be cancelled on such short notice. Its lawyers tried in vain to argue the intent of the deal trumped the significance of a comma. “This is clearly not what the parties intended,” Rogers said in a letter to the CRTC.

But to no avail. The CRTC lawyers, "armed with the rules of grammar and punctuation" decided that a comma setting off an adjunct clause from a conjoined structure necessarily gives it matrix scope, and if Rogers' contract lawyers didn't know that, too bad for them.

Does anyone know *what* prescriptive rule precisely is at issue here? Although the article mentions English textbooks and rules of grammar, no precise formulation of the relevant rule is given. Is it a sensible one? Or a foolish one?

I'm personally inclined to think it might be foolish. The description of the decision implies that the rule states something like this:

When an unless-clause modifies locally, it may not be set off from the clause it modifies by a comma.

That seems to imply that when an unless-clause is used unambiguously, locally modifying a simplex sentence, you are forbidden to use a comma to set it off. That is, the punctuation of the following sentence is incorrect:

Mary will ask John to the dance, unless he asks her first.

Contrast that with the commaless punctuation:

Mary will ask John to the dance unless he asks her first.

It actually seems to me that both are fine, AND that the comma makes a difference—the two sentences would be spoken with quite different intonation patterns (the first with nuclear stress on John and an intonation break before unless, the second with nuclear stress on first and no intonation break). Hence the commaless and commaful variants likely do have different structures at some level—but both are perfectly felicitous, and in both cases, the unless-clause is happily modifying the most local clause. Because the presence or absence of the comma is linguistically signiicant, though, no prescriptive rule should forbid it from preceding a locally-modifying unless-clause.

Then the real question is, can a conjoined sentence with an unless-clause spoken with the intonation break indicated by the comma allow modfication of the second conjunct only? Try for yourself:

Jane will ask Bill to the dance, and John will ask Sue, unless Phil asks Sue first.

In this situation, obviously the unless-clause is intended to modify only the second conjunct (since it would be pragmatically odd if Phil asking Sue to the dance had any bearing on whether Jane asks Bill). In my judgment, speaking the sentence with nuclear stress on the first occurrence of Sue, and with an intonation break before unless does not force the unless-clause to take matrix scope, thereby rendering the sentence pragmatically odd. Rather, the sentence is pragmatically natural, and the intended scope is perfectly accessible, with that intonation.

In my professional opinion then, Rogers has been unjustly done out of its $2.13 million; I think their contract language does permit the reading they thought they'd agreed to. On the other hand, there is no question that the matrix reading is also available (though, contra the court decision, it's not the only reading available). Further, it is the presence of the comma that makes the matrix reading available—the comma introduces ambiguity. Eliminating the comma would have eliminated the matrix reading, since the nuclear stress associated with the second conjunct would then have to fall in the unless-clause. So maybe the Rogers contract lawyers are really in the wrong after all, for letting such an ambiguity remain in their contract language. That's what they're getting the big bucks for, after all. They should have asked a linguist.

Update: Actually, now I think my example is not the best one to make this point. For a conjoined sentence to be true, both its conjuncts must be true. So truth-conditionally, it makes no difference whether the unless-clause in my example is attached locally to the second conjunct or to the matrix clause, taking scope over the first conjunct as well; [A and [B unless C]] has the same truth conditions as [[A and B] unless C]. Doesn't it? Though maybe the comma after A indicates that it is to be evauated as an independent proposition. Hmmm.

Update update: No, no, not so. [[A and B] unless C] is true if B and C come to pass but A doesn't. But [A and [B unless C]] is false in that situation. Phew. I think it's all ok & my original remarks stand.

Update update update And see the comments for a much better example with the temporal properties of the original from koldito. Also, Mark at the Language Log has weighed in on the matter, also suggesting the lawyers should have watched out for the ambiguity. But I still think that if the intended reading is available, and if common sense tells you that it WAS the intended reading, then the judge can't claim that the comma forces the matrix reading.

Update update update updateMark Liberman has now posted the text of (one version of) the actual rule in question, thanks to an alert reader, and it does say that a comma should be taken to indicate scope over the entire clause, and that otherwise one should follow the Law of the Last Antecedent. Looks like Late Closure was discovered in 1891 -- very sensibly surrounded with acknowledgements that the overall sense of the text should be taken into consideration. Not an adequate basis for a $2,000,000 decision, I would think!