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[lojban] Re: importing ro

la djorden. cusku di'e


The book is quite clear that ro as a quantifier is importing (16.8,
as pc has just pointed out on Jboske). Like you, my preference
would have been for nonimporting ro, but I can't see any grounds
for overriding the book -- it's not inconsistent or 'broken' on
this point.
It sure is inconsistent on this point. According to the book, 'ro pavyseljirna xirma cu blabi' is false, since 'ro pavyseljirna' has existential import, and thus 'naku ro pavyseljirna xirma cu blabi' is true, since it is the negation of a false statement. According to ch. 16 sec. 11, this is exactly equivalent to 'su'o pavyseljirna xirma naku blabi', which is false, since once again it claims existence of unicorns, and so either the book allows contradictions, and should be called 'the complete zenban language', or we can disregard that silliness about 'ro' having existential import, and use 'ro' as is standard in mathematics at least (whether or not that is the standard use in logic, as pc seems very certain that it is not). 


"naku ro pavyseljirna cu blabi" is not a true statement, because
it makes more claims than you are giving it credit for, and you
only contradicted one of them.  In fact, it's not even a true
statement with a nonimporting universal quantifier, if we keep our
negation boundary rules unchanged (more on this below).
"naku ro pavyseljirna xirma cu blabi" is the negation of "ro pavyseljirna xirma cu blabi", and so one of them must be true and the other false; that is simply the definition of negation. If ro has existential import, as the book seems to claim at first glance, then "ro pavyseljirna xirma cu blabi" is false, and its negation is true. This is not just Logic, but also what CLL says (15.2): "The most important rule about bridi negation is that if a bridi is true, its negation is false, and vice versa." [twice, a few paragraphs apart] (bridi negation is demonstrated to be putting 'na' in front of the selbri, which is elsewhere explained to be equivalent to putting 'naku' before the whole bridi.) 


It should be noted, btw, that:

	no pavyseljirna cu blabi

is a false statement because no imports also, since it can be moved
around.
If it is indeed false, then either 'su'o pavyseljirna' is not importing (probably not the best option), or 'no pavyseljirna' != 'naku su'o pavyseljirna', which is extremely counterintuitive, no matter how intuitive an importing ro might be. 


Actually the more I think about this the more I like importing
universals for lojban.  Take a look at the generalization of what
you were talking about:

	naku ro da poi gerku cu broda

Now; imagine that ro *doesn't* import.  The above sentence, then,
can't have the negation boundary moved:

	su'o da poi gerku naku broda

which claims there is at least one gerku.
If ro doesn't import, then your first sentence would use an importing "not all", since with the empty set for the set of gerku the sentence without "naku" is vacuously true, and thus its negation would be false. Therefore, there is no problem with equating that with the second sentence; both are importing. 


So what's really going on is what AndR says here, I think:  It is
"da" that imports, not ro.  Which is both consistent with book and
makes sense (and i'm even starting to like it better than nonimporting
foo).
It can be made consistent, but then we would have to drop the ability to move negation across quantifiers while switching the quantifier, which is also inconsistent with the book. 

mu'o mi'e .adam.