[lojban-beginners] Re: Implications of partly negated, commutative logical connections

[namor <eldrikdo@gmail.com>]

Am Donnerstag 03 Juli 2008 02:44:40 schrieb Jorge Llambías:
> Try:
>
> It is true that I like you if it is true that you love me.
>
> It is true that you love me only if it is true that I like you.


Yeah, this sounds much better. Just adding a 'it is true that' to the 
translation of each bridi denies the effect-cause relation.
Strange natlangs. :-)

> To talk about causality, don't use logical connectives. For example:
>
> mi nelci do .imu'ibo do prami mi
> I like you because you love me.
>
> da'i mi nelci do .iva'obo da'i do prami mi
> I would like you if you would love me.
>
> mu'o mi'e xorxes

I see.

If I understand right,
commutative logical connections with one side negated are mainly useful for 
observations in which you don't want to make any claims about causality.
{za'a le prenu cu gelki gi'anai citka}
I observe, It is true that the person is happy if it is true that the person 
eats
I observe, It is true that the person eats only if it is true that the person 
is happy

At first, one might think this is wrong, the English sentence "The person's 
happy if it eats" makes you think the person's eating is a cause of it's 
happiness.
But in fact, you only observed that the person is never not-happy if she eats.
So it is wrong to make claims about causality, for the eating could cause the 
happiness, or the happiness could cause the eating.

If I got it right,
the only difference to IFF/O connections is,
that the not negated bridi (part without na/nai) in the OR/A connection
can be true even if the other part is false.

So, if you observe both bridi all time and notice their truth values to be 
always same, you can use an IFF/O connection.
If you only observe the truth-value of bridi A all the time, but observe the 
truth-value of bridi B only while observing the one of bridi A at the same 
time (, but don't observe the truth-value of bridi B always!) (, and observe 
that if you observe both values at the same time, they are identical),
then you should use a OR/O connection with the part negated, which you observe 
all the time.

For instance,
you observe a friend is happy whenever he's with you:
{[za'a] le mi pendo cu gleki .gi'anai kansa mi}
It is true my friend is happy if it is true that he is with me
It is true that my friend is with me only if it is true he is happy

Maybe the friend a very happy person and always happy, we cannot know and do 
not claim this to be true or false.

Is the view on OR/A connections with one side negated right?


(ni'oru'e)
Is there a way to weaken a connection to something like: 'not always, but 
often/much of the time', the connection is true?

-- 
mu'o mi'e la namor e la'oi Rumpelstilzchen
.i mi to'e djica lonu mi miptera