[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [lojban-beginners] Question about {roda}



Oh, and keep in mind, we'd like to be able to be speaking basically the same Lojban that we speak day-to-day when we walk into a real analysis class. Try doing that in English and see how far you get.

mu'o mi'e .latros.

On Tue, Feb 22, 2011 at 8:36 AM, Ian Johnson <blindbravado@gmail.com> wrote:
Except that domain of discourse in general is quite explicit in logical or mathematical contexts. That is to say, you walk into (for example) an undergrad real analysis class and it is usually very explicit that that "for all x" means "for all x in R". When it isn't, it's always specified in one way or another; the original statement of the theorem you're discussing may be talking about a domain that is a compact interval, and then the "for all x" quantifies over that interval, since you're handing x to f. In more general contexts, such as set theory, "for all x" quantifies over literally everything that the theory causes to exist, such as the entire collection of sets.

These things don't bring up Lindar's issue of "which everything are we talking about?". If they did, mathematicians and logicians would be doing something else to alleviate it.

By contrast, in a general conversation, that universe of discourse is perhaps not some absolute one, but it is a very very large one, because a conversation could take twists and turns very very easily by comparison with a real analysis class. Thus the universe of discourse has to be an appropriate size to compensate for that.

I really think it isn't so hard, if you want to be lazy, to simply use {ro srana} and {da poi srana} (I forget, would {lo srana} suffice?). If you need a binding, {ro da poi srana} or {ro srana goi ko'a} work too.


mu'o mi'e .latros.

2011/2/21 Jorge Llambías <jjllambias@gmail.com>

On Mon, Feb 21, 2011 at 4:14 PM, Luke Bergen <lukeabergen@gmail.com> wrote:
> My only concern is that if {roda} has an implicite {poi co'e} then I'm not
> sure what you could put in for that {co'e} that gets you back to the strong
> EVERYTHING that logicians want.

What exactly is this strong everything? In Logic there is always a
domain of discourse for the variables to take their values from. See
for example http://en.wikipedia.org/wiki/Quantification

"In logic, quantification is the binding of a variable ranging over a
domain of discourse. The variable thereby becomes bound by an operator
called a quantifier."

Or: http://en.wikipedia.org/wiki/Domain_of_discourse

"In the formal sciences, the domain of discourse, also called the
universe of discourse (or simply universe), is the set of entities
over which certain variables of interest in some formal treatment may
range. The domain of discourse is usually identified in the
preliminaries, so that there is no need in the further treatment to
specify each time the range of the relevant variables."

You can't really do quantification without a domain of discourse.

> lojban makes it very easy to narrow a concepts meaning (with tanru, with
> poi/noi, with further bridi, etc...), but there are very few ways (none that
> my fever-addled brain can think of at the moment anyway) that expand a
> concepts meaning.  So if we take something as widely expanded as {ro} and
> say "oh, but it's not really universal all the time" then what CAN you say
> that is consistently universal?

"ro" says that the bridi is true for ALL the values in the universe of
discourse that the variable bound by the quantifier can take. Of
course it's consistently universal.

The problem seems to be that some people believe that there is some
absolute universal universe of discourse that includes all possible
universes of discourse or something like that, but there isn't.

mu'o mi'e xorxes

--
You received this message because you are subscribed to the Google Groups "Lojban Beginners" group.
To post to this group, send email to lojban-beginners@googlegroups.com.
To unsubscribe from this group, send email to lojban-beginners+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/lojban-beginners?hl=en.



--
You received this message because you are subscribed to the Google Groups "Lojban Beginners" group.
To post to this group, send email to lojban-beginners@googlegroups.com.
To unsubscribe from this group, send email to lojban-beginners+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/lojban-beginners?hl=en.