To summarize (I think): "I saw a plane flying over Zurich" is syntactically ambiguous (amphibolous) because it not clear whether the "flying over Zurich" modifies "I" or "a plane" (or, possibly, both). This is a grammatical fact which gives rise to a practical uncertainty: which proposition is being asserted, roughly, "When I was flying over Zurich, I saw a plane" or "I saw a plane when it was flying over Zurich". Lojban cannot create this uncertainty in the same way, since it cannot produce an amphibolous sentence, so, if it wants to create the same (or a practically similar) uncertainty, it must say, in effect "When either I or a plane were flying over Zurich, I saw the plane". Same uncertainty, but no amphiboly. (It is not quite the same uncertainty, since tgis asserts a definite proposition, whereas the original English failed to actually assert one, only presenting two possibilities, neither of them really put forward.)
There is a school of (incomplete) thought that holds that even this sentence fails to assert a proposition, since it is not completely fixed in space, time and circumstance (not perfectly pragmatically bound), but that means that no statement ever gives a complete proposition, since all the circumstances (which are infinite) can never be set forth. Thus, given that the context identifies me and thee, {mi prami do} does give a complete proposition, one sometimes true, sometimes false, and sometimes inappropriate. The worst that can be said of it is that it is vague, that something that ought to be specified Gricely is not. But, except in specially defined situations, there is nothing missing in this case, so it is not even vague. (Even the claim that 'prami' is inherently vague doesn't really apply, since those problems call for special circumstances again to rise to the level of relevance -- not that those circumstances are ever very far from view).
On Wednesday, January 28, 2015 7:26 AM, Jorge Llambías <jjllambias@gmail.com> wrote: