e'u lo'ai do ka sa'ai ka do le'ai

(Responding in English because discourse in lojban is painfully slow for me)

{lo do ka melbi} = {lo ka melbi ku pe do}
As I understand it, {ka melbi} can be {ka ce'u melbi} or {ka melbi ce'u}, the former of which doesn't make sense in context.

At least, that was my logic.

However, I will change the sentence, because your suggestion sounds better.

Well, either way is fine. It's like the distinction between "lo do zdani" and "lo zdani be do", except in this case, being more precise doesn't take up any more letters. :-)

u'u sai

Now that I read about properties again, I think my way of saying it is "archaic" (if there is such a thing in Lojban). When the object of a property is known, you're supposed to use "du'u" or "nu" rather than "ka". So that should probably be "lo du'u do melbi".

I feel like {du'u} is not appropriate here, because I think of {du'u} as "that" or "the fact that", so "ka" is more specific here.

If you can tell me what specifically you read, I may change my mind to agree with your new viewpoint.

There are two conflicting definitions here.

The CLL says things like "le ka do xunre [kei] cu cnino mi", which is what I've always used and what I suggested here. However, the CLL is quite old. In the errata, it says that this should be "du'u". (Surprisingly, this has not even been fixed in the updated CLL.)

L4B, on the other hand, says:

In older Lojban, you'll often see phrases like leka mi gleki for "the property of me being happy." That's because we used to not know any better (ce'u is a recent addition to the language), and were treating Lojban properties pretty much the way English does. The proper way to say this in Lojban is lenu mi gleki, or ledu'u mi gleki. Alternatively, if you want to emphasise that the property "x1 is happy" is being applied to you, you can say leka ce'u gleki kei poi ckaji mi — a literal translation of "the property 'x1 is happy' as applied to me".

Sources:

http://dag.github.com/cll/11/4/
http://www.tlg.uci.edu/~opoudji...ess15cehu.html