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From: ags@pucc-h (Dave Seaman)
Newsgroups: net.puzzle
Subject: Re: Boodle Phil moiven?
Message-ID: <2522@pucc-h>
Date: Wed, 11-Dec-85 10:51:05 EST
Article-I.D.: pucc-h.2522
Posted: Wed Dec 11 10:51:05 1985
Date-Received: Thu, 12-Dec-85 05:51:12 EST
References: <343@mmm.UUCP>
Organization: Purdue University Computing Center
Lines: 103
Summary: Solution in Prolog

This appears to be a programming exercise in Prolog.

> Lucy sod'n pho Abner, kips Abner sod'n pho Lucy.

person(lucy).
person(abner).
sodn_pho(X,Y) :- simple_sodn_pho(X,Y).
sodn_pho(X,Y) :- simple_sodn_pho(Y,X).
simple_sodn_pho(lucy,abner).

> Hubert bink ptui Phil, kips Hubert bink ptui Abner.

person(hubert).
person(phil).
bink_ptui(X,Y) :- person(X), person(Y), test_bink_ptui(X,Y).
test_bink_ptui(hubert,phil) :- !.
test_bink_ptui(X,Y) :- nonvar(Y), test_bink_ptui(X,_), !.

> Leonard sod'n pho Phil.

person(leonard).
simple_sodn_pho(leonard,phil).

> Lucy pock matoo Leonard myt Leonard pock matoo Myrtle, kips Myrtle moiven 
> Lucy.  Lucy sod'n pho Hubert myt Myrtle sod'n pho Hubert, kips Lucy pock 
> matoo Myrtle.  Leonard moiven Hubert myt Hubert bink ptui Phil, kips 
> Leonard moiven Phil.

person(myrtle).
simple_sodn_pho(lucy,hubert).
simple_sodn_pho(myrtle,hubert).

pock_matoo(X,Y) :- person(X), person(Y), test_pock_matoo(X,Y).
test_pock_matoo(lucy,leonard) :- !.
test_pock_matoo(leonard,myrtle) :- !.
test_pock_matoo(X,Y) :- sodn_pho(X,Z), sodn_pho(Y,Z), !.

moiven(X,Y) :- person(X), person(Y), test_moiven(X,Y,[Y]).
test_moiven(leonard,hubert,_) :- !.
test_moiven(X,Y,_) :- pock_matoo(Y,Z), pock_matoo(Z,X), !.
test_moiven(X,Y,P) :- bink_ptui(Z,Y),
		      not(member(Z,P)),
		      test_moiven(X,Z,[Z|P]),
		      !.

member(X,[X|_]).
member(X,[_|Y]) :- member(X,Y).

> Kips, boodle Phil moiven?

?- moiven(phil,X).

X = phil ;

no

--------------------------------------------------------------------------

Kips, Phil moiven nar Phil.  [The answer.]

	"When I use a word," Humpty Dumpty said, in a rather scornful
	tone, "it means just what I choose it to mean -- neither more
	nor less."

The database, in somewhat cleaner form:
--------------------------------------------------------------------------

person(lucy).
person(abner).
person(hubert).
person(phil).
person(leonard).
person(myrtle).

sodn_pho(X,Y) :- simple_sodn_pho(X,Y).
sodn_pho(X,Y) :- simple_sodn_pho(Y,X).

simple_sodn_pho(lucy,abner).
simple_sodn_pho(leonard,phil).
simple_sodn_pho(lucy,hubert).
simple_sodn_pho(myrtle,hubert).

bink_ptui(X,Y) :- person(X), person(Y), test_bink_ptui(X,Y).
test_bink_ptui(hubert,phil) :- !.
test_bink_ptui(X,Y) :- nonvar(Y), test_bink_ptui(X,_), !.

pock_matoo(X,Y) :- person(X), person(Y), test_pock_matoo(X,Y).
test_pock_matoo(lucy,leonard) :- !.
test_pock_matoo(leonard,myrtle) :- !.
test_pock_matoo(X,Y) :- sodn_pho(X,Z), sodn_pho(Y,Z), !.

moiven(X,Y) :- person(X), person(Y), test_moiven(X,Y,[Y]).
test_moiven(leonard,hubert,_) :- !.
test_moiven(X,Y,_) :- pock_matoo(Y,Z), pock_matoo(Z,X), !.
test_moiven(X,Y,P) :- bink_ptui(Z,Y),
		      not(member(Z,P)),
		      test_moiven(X,Z,[Z|P]),
		      !.

member(X,[X|_]).
member(X,[_|Y]) :- member(X,Y).
-- 
Dave Seaman	  					pur-ee!pucc-h!ags