FWIW, I recall the CLL mentioning that using lo and le in a manner analogous to "a" and "the", for back-referencing, is bad. I'm just not sure how many of you will agree with the CLL. (Also, I can't be bothered to look it up.)
{lo} *can* refer to things in context, and have definite referents. It's the *generic* article in the sense that we *don't know* if it's being definite or indefinite. The definite-indefinite distinction seems to slowly be dying in IRC Lojban, which is -- I'd wager -- where the majority of "spoken" Lojban happens. If there is such a thing as conversational Lojban, it's on IRC.
As for the "any" discussion, I'm slowly beginning to see the merits of sisku2 as a property. If we use a simple article plus a selbri, we invoke {zo'e} and somewhere, there are definite referents that appear. {.i mi sisku lo plise} has the awful problem of having semi-definite referents (quantifierless {lo} doesn't actually need to for strange xorlo reasons). However, assuming xorlo strangeness doesn't happen, the formal definition says we can plug in {zo'e noi ke'a plise} (the formal definition should change, IMVHO, to reflect the fact that {lo} can be quite bullshit-y.) -> {.i mi sisku zo'e noi ke'a plise}. Here's the proof that actual referents appear. {zo'e} has referents. Now, if any apple will do, there *shouldn't* be referents. Now, maybe it's possible to hack our way around this with {da}-magics, but it seems like invoking the property that is being searched for is a more succinct solution, as -- and here's the important part -- *any* object satisfying that predicate will work.
I haven't really analysed this to a greater degree that might suggest that using properties can most of the time / always work. I think however that exploring this possibility is worthwhile, unless we all get our facts straight about xorlo. (As it is, everyone has their own interpretation. Please don't say otherwise. In fact, I used to think I knew what I was talking about when I said "xorlo", but I realise that I don't. I used to think I agreed with certain people about xorlo, but I realise that I don't.)
.i mi'e la tsani mu'o
P.S. if this is going to degenerate into a full-blown discussion about articles and scopes and everything awful in the world, shouldn't we make a new topic?