On Tue, Feb 8, 2011 at 4:01 PM, Bob LeChevalier, President and Founder - LLG
<lojbab@lojban.org> wrote:
Alex Rozenshteyn wrote:
I was under the impression that {da broda brode} logically necessitates that {da brode}. Am I wrong?
The meaning of tanru (as opposed to their formal structure) is a semantics question, and it was explicitly decided that we would NOT get into prescribing rules for semantics.
It is NORMALLY the case for standard tanru, modeled after the most common English forms, that a broda brode is also just a brode. But it is not a logical or any other kind of necessity.
http://dag.github.com/cll/5/2/
explains that the fundamental basis of tanru meaning is "A type of B", but example 2.8 in that section includes one interpretation
"That is a table when it goes (otherwise it is a chair?)."
where it would be hard to say that B applies without the modifier A.
"fundamental basis" was not intended to be logical entailment, but rather more of a conceptual thing.
Section 15 is paired with the prior section, on asymmetrical tanru. Assymetrical tanru are ones where a tanru fits "A type of B" and thus comes closer to what you assumed, that, x1 could be said to be B, omitting the modifier. But even there, a "rirxe xirma", "river horse" = hippopotamus is not really a horse.
Is a hippopotamus even a {rirxe xirma}? I know the etymology of the English (et al.) suggests 'river horse', but is that carried over to Lojban? I would expect a more literal interpretation of the tanru, namely 'a river type of horse'. Since hippopotamuses aren't horses (or xirma), they aren't rirxe xirma either.
stevo
Section 15 indicates that most of its examples might be (better) expressible with a logical or non-logical connective between the components. As usage has developed, probably such a connective would be used by a Lojbanist, but that isn't part of the language prescription. This is probably more significant when tanru are made into lujvo, where a brodybrode is not necessarily a brode, and connective rafsi are usually omitted.
lojbab
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Bob LeChevalier lojbab@lojban.org www.lojban.org
President and Founder, The Logical Language Group, Inc.