[lojban-beginners] Re: "djuno najo cusku"

[Minimiscience <minimiscience@gmail.com>]

de'i li 18 pi'e 06 pi'e 2009 la'o fy. David Gowers .fy. cusku zoi skamyxatra.
> I was just looking at
> http://www.lojban.org/tiki/tiki-index.php?page=LojbanAphorisms
> 
> and found
> "djuno najo cusku"
> which supposedly means "Those who say, don't know; those who know, don't
> say"
> However I translate it more like "those who say, don't know" (and that's
> all).
> It seems to me that
> "djuno jonai cusku"
> fits the translation better (djuno XOR cusku -- ie know if not say, say if
> not know)
.skamyxatra

"{najo}" and "{jonai}" are essentially the same thing; "(NOT p) IFF q" is
logically equivalent to "p IFF (NOT q)", which are both equivalent to "p XOR
q."

> of course you could also do the excessively verbose
> "djuno najo cusku .e cusku najo djuno" to express the idea.

Two things:

1. The logical connectives for a given type of connection ({sumti}, {tanru},
   etc.) all have the same precedence and are left-associative.  Thus, that
   utterance corresponds to "((djuno XOR cusku) AND cusku) XOR djuno)", which
   happens to simplify to "djuno OR cusku," i.e., "{djuno ja cusku}."  To get
   around this, either attach "{bo}" to each "{najo}" (technically, only the
   second one needs it, but attaching to both is better for symmetry), or put a
   "{ke}" after the "{.e}."

2. You're mixing a {tanru} connective ("{najo}") with a {sumti} connective
   ("{.e}") inside a {tanru}.  Either change the "{.e}" to "{je}" or otherwise
   reword the utterance (e.g., something like "{lonu djuno najo cusku .e lonu
   cusku najo djuno}").

mu'omi'e .kamymecraijun.

-- 
ko kutygau le do skami jbipru bo vreji