Re: LOGO-L> Logical Puzzle

[George Mills <mills@softronix.com>]

This is Brian's cup of tea, if you will.

Check out MSWLogo\Examples\UCBLogo\Math.LGO

This is also what Prolog is all about (that was discussed a while back).
Note that you can define Math itself as logic problems as well.

Olga Tuzova wrote:
> 
> Hello everybody,
> 
> I'm intruding on your recursion discussion with very different problem.
> I haven't seen this kind of problems there, but may be somebody is
> interested, or has had an experience in solving them.
> The problem is from a "logical field".
> 
> For example let's formulate it as follows.
> 
> Three experts are having discussion about an ancient cup.
> 
> Expert A: This is a China cup from the 5th century,
> Expert B: This is a Japan cup from the third century,
> Expert C: This is not a China cup, it was made in the 4th century.
> 
> It turned out, only one of two statements of each expert was right, the
> other was wrong.
> 
> What country and what century does the cup belong?
> ----------------
> 
> I think, the main idea of the solution is standart.
> 
> Le's denote with C the statement "the cup is from China",
>             J - "from Japan",
>             T - "it was made in the third century",
>             F - " in the 4th century",
>             V - " in the 5th century".
> 
> We should find such boolean values of C J T F V, which make the
> following statements  "true":
>     or (and C not V)(and not C V)
>     or (and J not T)(and not J T)
>     or (and not not C F)(and not C not F)
> Also:
>     not and T F
>     not and T V
>     not and F V
>     not and C J.
> 
> The solutions that I've seen, all use looking over(?) all the possible
> combinations of values of C, J, T, F, V. It doesn't look great. I tried
> to present these combination as a binary code (binary representation of
> the number from 0 through 31), but not sure it improves the solution
> much.
> Would be greatful for any ideas and suggestions. Also, does anybody work
> on such problems this way or other with the school children?
> 
> The solution presented below, says, that the cup was from Japan and was
> made in the 5th century.
> 
> Thanks,
> Olga.
> ---------------------------------
> to logic.main
> for [i 0 31][if (and bool1 c :i v :i ~
>                      bool1 j :i t :i ~
>                      bool2 c :i f :i ~
>                      bool3 c :i j :i ~
>                      bool3 t :i f :i ~
>                      bool3 t :i v :i ~
>                      bool3 f :i v :i)~
>             [(pr c :i j :i t :i  f :i v :i)]]
> end
> 
> to c :i
> op int :i/16
> end
> 
> to j :i
> op remainder int :i/8 2
> end
> 
> to t :i
> op remainder int :i/4 2
> end
> 
> to f :i
> op remainder int :i/2 2
> end
> 
> to v :i
> op remainder :i 2
> end
> 
> to bool1 :c :v
> output or (and l :c not l :v) (and l :v not l :c)
> end
> 
> to bool2 :c :f
> output or (and not not l :c l :f)(and not l :c not l :f)
> end
> 
> to bool3 :c :j
> output not and l :c l :j
> end
> 
> to l :a
> ifelse :a=1 [op "true][op "false]
> end
> -------------------------------
> 
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-- 
===============================================================
George Mills
email: mills@softronix.com
http://www.softronix.com
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