Re:‘Saluton’: the surprise return of Esperanto
by yorwba on Thursday December 28, 2017 @03:41AM
(#16021005)
I don't know any Lojban at all, but I do know formal logic and "there exists" (∃) is usually used to denote existence with respect to some universe of discourse, and not necessarily physical existence. Most mathematical concepts only exist as things that mathematicians talk about, not unlike Unicorns. However, I would read the example sentence as making a statement about all unicorns, of the form "∀ U ∈ Unicorns . U ∈ MythicalCreatures ∧ (∃ H ∈ Horses . looks-like(U, H)) ∧ ∃ H ∈ Horns . (has(U, H) ∧ ∃F ∈ Foreheads . (has(U, F) ∧ coming-out-of(H, F)))" or something to that effect.
The sentence about counterexamples to Fermat's last theorem could be written using an existential quantifier without problem, since it appears in a negated sentence, thus not actually claiming their existence, rather the nonexistence of counterexamples discovered prior to 1993.
However, looking at the definition you linked, it appears that "lo" does not have any specific equivalent in formal logic since "It converts a selbri, selecting its first argument, into a sumti. The resulting expression refers generically to any or some individual or individuals that fit as the first argument of the selbri." which seems to be mostly a grammatical function?
First, I think "lo cmalu noltru" is a sumti (akin to a noun phrase) and not a complete sentence by itself.
Second, I'm not positive about the existential import of "lo". There are many reasons for this, but to take a kind of extreme example, the reform of the meaning of le and lo at https://mw.lojban.org/papri/BPFK_Section:_gadri#cmavo:_lo_.2... presents the example
lo pavyseljirna cu ranmi danlu gi'e simlu lo ka ge ce'u xirma gi lo pa jirna cu cpana lo mebri be ce'u
'Unicorns are mythical creatures that look like a horse with a horn coming out of their foreheads.'
This doesn't seem to imply that there exists X such that X satisfies the predicate pavyseljirna. Or to take another example, presumably Lojban can express using "lo" the notion that "Counterexamples to Fermat's Last Theorem were never discovered prior to 1993, despite extensive computer searches".
I do think that many Lojban utterances have formal existential import in many cases, and I don't know enough about Lojban to try to describe which ones. :-) (I seem to remember something about a bare gismu implying that the predicate is at some occasion true of something, like "tavli" by itself without arguments meaning something like 'speaking, it's a thing that happens at some point!'. But given the example of talking about unicorns, maybe even this is too strong somehow.)
Edit: ... by the way, what's the conlang with two speakers that you speak?