“At Least One of X and Y”: The Semantics Train Wreck That Is the Federal Circuit’s 2004 Opinion in SuperGuide Corp. v. DirecTV Enterprises, Inc.

I got another tip from a participant at the recent “Drafting Clearer Contracts” seminar in Houston, although I didn’t have the wit to note his name.

He suggested that I check out the 2004 opinion in SuperGuide Corp. v. DirecTV Enterprises, Inc., by then Circuit Judge (now Chief Circuit Judge) Sharon Prost of the United States Court of Appeals for the Federal Circuit; for a PDF, go here. (The Federal Circuit is the only appellate-level court with the jurisdiction to hear appeals in patent cases.) This opinion involves the semantics of at least one of X and Y, which is something I hadn’t previously had occasion to look into.

A Patent Case?

But SuperGuide is a patent case! Patent claims aren’t contracts, so why am I bothering to look at it? Consider what the SuperGuide court said:

There is a “heavy presumption” that the terms used in claims “mean what they say and have the ordinary meaning that would be attributed to those words by persons skilled in the relevant art.”

So the SuperGuide court considered the “ordinary meaning” of at least one of X and Y. (The business about “would be attributed to those words by persons skilled in the relevant art” is irrelevant in this context, as we’re dealing with everyday English and not technical or scientific terminology.) It wouldn’t be surprising if a court considering the same issue in the context of a dispute over contract interpretation were to consider what SuperGuide has to say. That makes SuperGuide potentially relevant for purposes of contracts.

The Court’s Analysis

Let’s consider the opinion. I won’t summarize the facts, as that would take too much of your time and mine. Instead, I’ll focus on the semantics.

Here’s part of the language at issue:

An online television program schedule system comprising:

first means for storing at least one of a desired program start time, a desired program end time, a desired program service, and a desired program type; …

Does this refer to storing at least one unit within each of the four categories, or storing at least one category?

Here’s what the court said (footnotes and citations omitted):

In interpreting this phrase, the district court concluded that the term “a desired,” which precedes “at least one of,” is repeated for each category and because the final category in the criteria list is introduced by “and a desired,” the list is conjunctive. The court also concluded that accepting SuperGuide’s position that “at least one of” refers only to one category of the criteria would contradict the purpose of the invention as described in the written description, as depicted in Figure 4a and recited in claim 1. Thus, the court construed the phrase “at least one of … and” as meaning “at least one of each desired criterion; that is, at least one of a desired program start time, a desired program end time, a desired program service and a desired program type. The phrase does not mean one or more of the desired criteria but at a minimum one category thereof.”

On appeal, SuperGuide contends that the claim phrase “at least one of” unambiguously requires the selection and storage of one or more of the four listed criteria (start time, end time, service channel, or type) and does not require storing all four criteria. …

DirecTV counters that the district court’s construction is supported by the patentee’s use of the conjunctive word “and” and by the grammatical rule requiring that the phrase “at least one of” be applied to each category in the list. …

…

We agree with DirecTV. The phrase “at least one of” precedes a series of categories of criteria, and the patentee used the term “and” to separate the categories of criteria, which connotes a conjunctive list. A common treatise on grammar teaches that “an article of [sic] a preposition applying to all the members of the series must either be used only before the first term or else be repeated before each term.” William Strunk, Jr. & E.B. White, The Elements of Style 27 (4th ed. 2000). Thus, “[i]n spring, summer, or winter” means “in spring, in summer, or in winter.” Applying this grammatical principle here, the phrase “at least one of” modifies each member of the list, i.e., each category in the list. Therefore, the district court correctly interpreted this phrase as requiring that the user select at least one value for each category; that is, at least one of a desired program start time, a desired program end time, a desired program service, and a desired program type.

The court also suggested that the outcome would have been different if the language at issue had used as a conjunction or instead of and. Specifically, in footnote 10 the court said, “SuperGuide does not articulate its argument that ‘at least one of’ means ‘one or more of the four listed criteria’ without using the term ‘or’ to separate the four listed categories.” It then noted that an earlier Federal Circuit decision had interpreted a claim constructed as “at least one of A, B, or C” as covering only A, only B, only C, or any combination of the three.

My Analysis—Ambiguity

The court’s analysis makes no sense. First, the passage in The Elements of Style is irrelevant. All it does is say that as a matter of writing style it would be awkward to say “in spring, summer, or in winter” instead of one of the two alternatives the court quoted. It has nothing to do with identifying ambiguity.

And second, of course the phrase “at least one of” modifies each member of the list. That’s not the issue. Instead, the issue is whether “one of” refers to an item within a category or to the category itself.

So the “Therefore” that begins the final sentence of the extract above is unearned—nothing has been demonstrated.

The meaning suggested by SuperGuide is the more natural reading, but I could imagine a not-particularly-skilled drafter wording it that way even if they had intended to express the DirecTV meaning. So I could imagine a court holding that the language at issue conveys the SuperGuide meaning or holding that it’s ambiguous. The one conclusion that’s implausible is the one the court arrived at—that the language at issue conveys unambiguously the meaning sought by DirecTV.

My Analysis—Conjunctions

And there’s the court’s suggestion that the outcome would have been different if the language at issue had used or instead of and. That too makes no sense. For one thing, as described above, the possible alternative meanings of the language at issue don’t arise from use of and.

Furthermore, and is actually the logical choice. Let’s explore how this plays out, first by considering use of at least one of X and Y with units, a use that wasn’t at issue in SuperGuide:

[1a]        at least one of Tom, Dick, and Harry

[1b]        at least one of Tom, Dick, or Harry*

The reference is to at least one of a group, making and the appropriate choice, as in [1a]. Using or instead would suggest that one is referring to at least one out of one of the three. That doesn’t make sense. Option 1[b] is illogical—hence the asterisk.

Now let’s consider use of at least one of X and Y with categories—in other words language analogous to that at issue in SuperGuide, but written to make it clear whether what is being referred to is the categories or units in the categories.

Here are examples that refer to the categories (analogous to the meaning sought by SuperGuide):

[2a]        at least one of the following categories: nuts, bolts, and screws

[2b]        at least one of the following categories: nuts, bolts, or screws*

Again, the example using and is the logical choice. The example using or is the illogical choice, as it suggests that one is referring to at least one out of one of the three categories. It follows that the SuperGuide court is doubly mistaken in suggesting that SuperGuide could have expressed the intended meaning only by using or.

Now let’s consider examples that refer to units in the categories:

[3a]        at least one unit in each of the following categories: nuts, bolts, and screws

[3b]        at least one unit in each of the following categories: nuts, bolts, or screws*

[3c]        at least one unit in the category nuts, the category bolts, or the category screws*

[3d]        at least one unit in [at least] one of the following categories: nuts, bolts, and screws

Example [3a] is analogous to the meaning sought by DirectTV. Here, too, using or, as in [3b], is the less defensible choice, and for the same reason that [2b] is less logical than [2a]. You could use or to convey a different meaning, as in [3c], but it would be clearer to use and to convey that same meaning, as in [3d].

One commentator on English usage has in the past offered an analysis that conflicts with my analysis of [1a] and [1b] (and, by extension, the subsequent examples). In the second edition of Bryan Garner’s A Dictionary of Modern Legal Usage, the entry for later of [date] or [date]; later of [date] and [date]—a construct analogous to at least one of X and Y—says as follows:

Drafters frequently debate whether the proper conjunction in this phrase is or or and. The better idiomatic choice is or—nine of every ten lawyers believing it is the proper choice.

True, and has logic on its side. If we paraphrase by saying the later of two dates, it becomes clear that the sense must be plural (conjunctive and), not singular (disjunctive or). But the wording with and sounds as pedantic—and as wrong—as a number of people was there.

This analysis exhibits three shortcomings. First, recommending usages based on their popularity sounds alarmingly descriptive coming from the essentially prescriptive Garner. Second, to my ear using and sounds just fine, and my ear has served me well over the years, but more to the point, it’s a cop-out to invoke the “sound” of a usage and nothing more. And third, the comparison with a number of people was there is unhelpful, like any comparison of apples and oranges. So I’ll go with the logical alternative, and. It’s perhaps not surprising this entry didn’t make it into the third edition of what is now called Garner’s Dictionary of Legal Usage. [Correction 7 February 2017: Actually, it’s in the third edition.]

Drafting Recommendation

The court’s opinion in SuperGuide is unfortunate in two respects. For one thing, with respect to this part of the opinion at least, SuperGuide was deprived of justice. But more generally, this opinion has set an unhelpful precedent by suggesting that the outcome would have been different if the language at issue had used as a conjunction or instead of and. In fact, the seminar participant who told me about SuperGuide mentioned that he and his colleagues assume one should always use or with at least one of.

Here’s what I recommend: Use only at least one of X and Y. Don’t use or. To avoid problems, pay attention to how you use this phrase. If you’re referring to units, as in [1a], there’s nothing to consider—the meaning is clear and furthermore SuperGuide doesn’t apply. If you use it regarding categories, make it explicit that you’re referring to categories, as in [2a]. If you use it regarding units within categories, make it explicit that you’re referring to units, and furthermore make it clear whether you’re referring to units in all the categories, as in [3a], or fewer than all, as in [3d].

And by the way, you can convey the same meaning as at least one of X and Y by saying one or more of X and Y. The same analysis applies to both formulations. I prefer the latter, just because it seems a bit simpler.

Policy Recommendation

As I explain in this 2009 post, courts generally hold that (1) no expert testimony of any kind is admissible to determine whether contract language is ambiguous and (2) in the case of contract language that isn’t ambiguous, expert testimony is admissible only to determine technical meaning.

We see how that worked out in SuperGuide. And although the semantics failure on display in SuperGuide is particularly apparent, there’s no shortage of opinions in which judges mishandle analysis of ambiguity. For two relatively recent examples from appellate opinions, see this forthcoming article about an opinion of the U.S. Court of Appeals for the Second Circuit and this article about an opinion of the Third Circuit.

The explanation is simple enough—diagnosing ambiguity, or alleged ambiguity, requires semantic acuity. Even though the language in SuperGuide was actually straightforward, it was more than the SuperGuide court could handle.

So what I say in my 2009 post holds true:

Just because a judge drives a car, that doesn’t make the judge an expert in automobile engineering. Similarly, the fact that a judge speaks and writes English doesn’t mean the judge is wise to the many ways that ambiguity can manifest itself in contracts.

To help avoid messes such as SuperGuide, judges should accept that much of the judiciary isn’t equipped to analyze ambiguity and that expert testimony can provide guidance. (And by the way, citing Strunk & White is not a good sign; see this takedown by Geoff Pullum.)

And litigators should recognize that they, too, are generally not well equipped to analyze ambiguity. If expert testimony on ambiguity isn’t admissible, litigators should make sure they have on hand appropriate expertise, so it informs their pleadings.

[Updated June 10, 2015: In this June 5, 2015 post I expand on the point I make in the final paragraph.]