Subject: Re: [lojban] A or B, depending on C, and related issues

From: "Jorge Llambias" <[email-masked]>
Date: Fri, 10 Aug 2001 02:17:57

la pycyn cusku di'e

> > [(if P then Q) and (if not P then R)] xor
> > [(if not P then Q) and (if P then R)]
>
>Since this
>all is out of the {makau} thread, which is about hiding significant
>information, perhaps that is an important fact, but then we need to see how
>these connections are going to work: (if Pkau then Q) and (if not-Pkau then
>R)?

No, Pkau is always true, so that one would reduce to (Q and R).

>The best simplification I could find in a dash was ~(Q&R) &(P => QvR) ,
>which, while shorter, is markedly less informative when talking about
>depndencies.

Actually, that reduction fails when P, Q, and R are false.
(It gives true, should give false.)

The actual reduction, funnily enough, turns out to be (Q xor R),
independent of P!

What's more, this other one:

[(P iff Q) and (not P iff R)] xor [(not P iff Q) and (P iff R)]

also reduces to the same thing: (Q xor R).

This makes sense, because the truth value of "Q or R depending on P"
cannot depend on the truth value of P, since we are not specifying
what the dependency is. This fits in very nicely with the Pkau
interpretation, which might be:

Pkau => (Q xor R)

mu'o mi'e xorxes

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