# How to appropriately arrange this description

I wish to describe a theorem of somebody X and also the statement of the theorem, and my first attempt is something like a theorem of X that gives a lower bound of ... . Then I immediately realized that such description will induce some confusion about the antecedent of that. At length I reached the formulation a theorem that belongs to X and that gives a lower bound of .... It is, however, sounds no idiomatic and annoying. So I wish to know the optimal way to present what I wish to present.

Moreover, is there any general rule guiding the usage for relative pronouns with possible multi-antecedent?

Thanks so much.

• Unless X is very heavy (like 3-5 words or more), I think it's unlikely for the reader to think that it's X that gives a lower bound. It's a bit difficult to tell by seeing just an X, not the real stuff. (By the way, I think you're probably talking about a theorem that gives the lower bound, not a lower bound. I'm not sure though, I don't know how many bounds are possible in your context.) If your X is very long, it might be better to describe your theorem in two sentences (or more). Jul 5 '14 at 8:53
• Much appreciated. But, Damkerng, with no offense I wish to avoid English native speakers' confusion. I am also not a native speaker in English, and from experience I have realized that many details that I consider okay cause native speakers' confusion~ Jul 5 '14 at 9:27

Your original construction will not cause confusion.

Relative that can only head a restrictive relative clause, a clause required to distinguish the noun or NP to which it refers from all other entities which that noun or NP might refer to. But:

1. The names of persons are usually unique, so there is rarely any need to distinguish this X from all other Xs, particularly within the fairly narrow set of people capable of composing mathematical theorems.

2. Even if there were two or more mathematicians of the same name as X, if your author were to be distinguished with a restrictive relative clause his name would have to be preceded by the definite article the, thus:

... a theorem of the X that gives a lower bound of ...

Consequently, it is not likely to enter anyone's mind that the that clause refers to X.

But if you insist on making assurance doubly sure, you may disambiguate even further by replacing that with whichwhich never refers to individual persons.

`<rant>`
Indeed, my own recommendation is that you replace relative that with who, whom or which, whichever is appropriate, on all occasions. My reasons are given here. But it is only fair to say that few academics would endorse that recommendation.
`</rant>`