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

[pycyn@aol.com]

In a message dated 8/9/2001 6:24:35 PM Central Daylight Time,
jjllambias@hotmail.com writes:

"if P then Q, else R," which are also pleasantly simple:
>(if P then Q) and (if not P then R)" and "(P iff Q) and (not P iff R)"  
>While
>I am sure there are easier ways to show that these are the simplest forms
>for
>these functions, I confess to just having run all the possibilities from
>disjunctive normal forms on down.

Neither of them is "Q or R, depending on P" though. One of
the versions of that would be:

[(if P then Q) and (if not P then R)] xor
[(if not P then Q) and (if P then R)]

Well, they are in fact the two things that I usually see when I ask for an
explanation of that phrase, and they do fit the requirements.  I admit the
other is more thorough sounding, but does it really introduce a new
possibility in the concrete?  Similarly, is the "P or Q, depending on the
weather" more than an inspecific way to saying something of the first or
second sort -- just failing to mention how the dependency goes.   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)?

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.