37 lines
1.2 KiB
Factor
37 lines
1.2 KiB
Factor
! Copyright (C) 2019-2020 KUSUMOTO Norio.
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! See http://factorcode.org/license.txt for BSD license.
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USING: logic lists ;
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IN: logic.examples.zebra-short
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! Do the same as this Prolog program
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!
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! neighbor(L,R,[L,R|_]).
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! neighbor(L,R,[_|Xs]) :- neighbor(L,R,Xs).
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!
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! zebra(X) :- Street = [H1,H2,H3],
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! member(house(red,english,_), Street),
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! member(house(_,spanish,dog), Street),
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! neighbor(house(_,_,cat), house(_,japanese,_), Street),
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! neighbor(house(_,_,cat), house(blue,_,_), Street),
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! member(house(_,X,zebra),Street).
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LOGIC-PREDS: neighboro zebrao ;
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LOGIC-VARS: L R X Xs H1 H2 H3 Street ;
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SYMBOLS: red blue ;
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SYMBOLS: english spanish japanese ;
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SYMBOLS: dog cat zebra ;
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TUPLE: house color nationality pet ;
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{ neighboro L R L{ L R . __ } } fact
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{ neighboro L R L{ __ . Xs } } { neighboro L R Xs } rule
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{ zebrao X } {
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{ (=) Street L{ H1 H2 H3 } }
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{ membero [ T{ house f red english __ } ] Street }
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{ membero [ T{ house f __ spanish dog } ] Street }
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{ neighboro [ T{ house f __ __ cat } ] [ T{ house f __ japanese __ } ] Street }
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{ neighboro [ T{ house f __ __ cat } ] [ T{ house f blue __ __ } ] Street }
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{ membero [ T{ house f __ X zebra } ] Street }
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} rule
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