19 lines
422 B
Factor
19 lines
422 B
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 kernel lists assocs math ;
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IN: logic.examples.fib
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LOGIC-PREDS: fibo ;
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LOGIC-VARS: F F1 F2 N N1 L ;
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{ fibo N L{ F F1 F2 . L } } {
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{ (>) N 1 }
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[ [ N of 1 - ] N1 is ]
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{ fibo N1 L{ F1 F2 . L } }
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[ [ [ F1 of ] [ F2 of ] bi + ] F is ] !!
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} rule
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{ fibo 0 L{ 0 } } !! rule
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{ fibo 1 L{ 1 0 } } fact
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