394 lines
		
	
	
		
			8.5 KiB
		
	
	
	
		
			Factor
		
	
	
			
		
		
	
	
			394 lines
		
	
	
		
			8.5 KiB
		
	
	
	
		
			Factor
		
	
	
| ! Copyright (C) 2004, 2010 Slava Pestov.
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| ! See http://factorcode.org/license.txt for BSD license.
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| USING: math kernel math.constants math.private math.bits
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| math.libm combinators fry math.order sequences ;
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| IN: math.functions
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| 
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| GENERIC: sqrt ( x -- y ) foldable
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| 
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| M: real sqrt
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|     >float dup 0.0 <
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|     [ neg fsqrt [ 0.0 ] dip rect> ] [ fsqrt ] if ; inline
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| 
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| : factor-2s ( n -- r s )
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|     ! factor an integer into 2^r * s
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|     dup 0 = [ 1 ] [
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|         [ 0 ] dip [ dup even? ] [ [ 1 + ] [ 2/ ] bi* ] while
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|     ] if ; inline
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| 
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| <PRIVATE
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| 
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| : (^fixnum) ( z w -- z^w )
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|     [ 1 ] 2dip
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|     [ dup zero? ] [
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|         dup odd? [
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|             [ [ * ] keep ] [ 1 - ] bi*
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|         ] when [ sq ] [ 2/ ] bi*
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|     ] until 2drop ; inline
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| 
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| : (^bignum) ( z w -- z^w )
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|     make-bits 1 [ [ over * ] when [ sq ] dip ] reduce nip ; inline
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| 
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| : (^n) ( z w -- z^w )
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|     dup fixnum? [ (^fixnum) ] [ (^bignum) ] if ; inline
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| 
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| GENERIC# ^n 1 ( z w -- z^w ) foldable
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| 
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| M: fixnum ^n (^n) ;
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| 
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| M: bignum ^n
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|     [ factor-2s ] dip [ (^n) ] keep rot * shift ;
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| 
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| M: ratio ^n
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|     [ >fraction ] dip '[ _ ^n ] bi@ / ;
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| 
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| M: float ^n (^n) ;
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| 
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| M: complex ^n (^n) ;
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| 
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| : integer^ ( x y -- z )
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|     dup 0 >= [ ^n ] [ [ recip ] dip neg ^n ] if ; inline
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| 
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| PRIVATE>
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| 
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| : >float-rect ( z -- x y )
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|     >rect [ >float ] bi@ ; inline
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| 
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| : >polar ( z -- abs arg )
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|     >float-rect [ [ sq ] bi@ + fsqrt ] [ swap fatan2 ] 2bi ; inline
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| 
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| : cis ( arg -- z ) >float [ fcos ] [ fsin ] bi rect> ; inline
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| 
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| : polar> ( abs arg -- z ) cis * ; inline
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| 
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| GENERIC: e^ ( x -- y )
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| 
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| M: float e^ fexp ; inline
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| 
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| M: real e^ >float e^ ; inline
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| 
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| M: complex e^ >rect [ e^ ] dip polar> ; inline
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| 
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| <PRIVATE
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| 
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| : ^mag ( w abs arg -- magnitude )
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|     [ >float-rect swap ]
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|     [ >float swap >float fpow ]
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|     [ rot * e^ /f ]
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|     tri* ; inline
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| 
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| : ^theta ( w abs arg -- theta )
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|     [ >float-rect ] [ flog * swap ] [ * + ] tri* ; inline
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| 
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| : ^complex ( x y -- z )
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|     swap >polar [ ^mag ] [ ^theta ] 3bi polar> ; inline
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| 
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| : real^? ( x y -- ? )
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|     2dup [ real? ] both? [ drop 0 >= ] [ 2drop f ] if ; inline
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| 
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| : 0^ ( zero x -- z )
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|     swap [ 0/0. ] swap '[ 0 < 1/0. _ ? ] if-zero ; inline
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| 
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| : (^mod) ( x y n -- z )
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|     [ make-bits 1 ] dip dup
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|     '[ [ over * _ mod ] when [ sq _ mod ] dip ] reduce nip ; inline
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| 
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| PRIVATE>
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| 
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| : ^ ( x y -- z )
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|     {
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|         { [ over zero? ] [ 0^ ] }
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|         { [ dup integer? ] [ integer^ ] }
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|         { [ 2dup real^? ] [ [ >float ] bi@ fpow ] }
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|         [ ^complex ]
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|     } cond ; inline
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| 
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| : nth-root ( n x -- y ) swap recip ^ ; inline
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| 
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| : lcm ( a b -- c )
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|     [ * ] 2keep simple-gcd /i ; foldable
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| 
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| : divisor? ( m n -- ? )
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|     mod 0 = ; inline
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| 
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| ERROR: non-trivial-divisor n ;
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| 
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| : mod-inv ( x n -- y )
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|     [ nip ] [ gcd 1 = ] 2bi
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|     [ dup 0 < [ + ] [ nip ] if ]
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|     [ non-trivial-divisor ] if ; foldable
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| 
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| : ^mod ( x y n -- z )
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|     over 0 <
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|     [ [ [ neg ] dip ^mod ] keep mod-inv ] [ (^mod) ] if ; foldable
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| 
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| GENERIC: absq ( x -- y ) foldable
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| 
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| M: real absq sq ; inline
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| 
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| : ~abs ( x y epsilon -- ? )
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|     [ - abs ] dip < ;
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| 
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| : ~rel ( x y epsilon -- ? )
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|     [ [ - abs ] 2keep [ abs ] bi@ + ] dip * <= ;
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| 
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| : ~ ( x y epsilon -- ? )
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|     {
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|         { [ dup zero? ] [ drop number= ] }
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|         { [ dup 0 < ] [ neg ~rel ] }
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|         [ ~abs ]
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|     } cond ;
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| 
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| : conjugate ( z -- z* ) >rect neg rect> ; inline
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| 
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| : arg ( z -- arg ) >float-rect swap fatan2 ; inline
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| 
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| : [-1,1]? ( x -- ? )
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|     dup complex? [ drop f ] [ abs 1 <= ] if ; inline
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| 
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| : >=1? ( x -- ? )
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|     dup complex? [ drop f ] [ 1 >= ] if ; inline
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| 
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| GENERIC: frexp ( x -- y exp )
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| 
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| M: float frexp
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|     dup fp-special? [ dup zero? ] unless* [ 0 ] [
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|         double>bits
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|         [ 0x800f,ffff,ffff,ffff bitand 0.5 double>bits bitor bits>double ]
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|         [ -52 shift 0x7ff bitand 1022 - ] bi
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|     ] if ; inline
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| 
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| M: integer frexp
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|     [ 0.0 0 ] [
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|         dup 0 > [ 1 ] [ abs -1 ] if swap dup log2 [
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|             52 swap - shift 0x000f,ffff,ffff,ffff bitand
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|             0.5 double>bits bitor bits>double
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|         ] [ 1 + ] bi [ * ] dip
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|     ] if-zero ; inline
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| 
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| DEFER: copysign
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| 
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| GENERIC# ldexp 1 ( x exp -- y )
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| 
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| M: float ldexp
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|     over fp-special? [ over zero? ] unless* [ drop ] [
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|         [ double>bits dup -52 shift 0x7ff bitand 1023 - ] dip +
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|         {
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|             { [ dup -1074 < ] [ drop 0 copysign ] }
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|             { [ dup 1023 > ] [ drop 0 < -1/0. 1/0. ? ] }
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|             [
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|                 dup -1022 < [ 52 + -52 2^ ] [ 1 ] if
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|                 [ -0x7ff0,0000,0000,0001 bitand ]
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|                 [ 1023 + 52 shift bitor bits>double ]
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|                 [ * ] tri*
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|             ]
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|         } cond
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|     ] if ;
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| 
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| M: integer ldexp
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|     2dup [ zero? ] either? [ 2drop 0 ] [ shift ] if ;
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| 
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| GENERIC: log ( x -- y )
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| 
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| M: float log dup 0.0 >= [ flog ] [ 0.0 rect> log ] if ; inline
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| 
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| M: real log >float log ; inline
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| 
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| M: complex log >polar [ flog ] dip rect> ; inline
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| 
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| <PRIVATE
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| 
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| : most-negative-finite-float ( -- x )
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|     -0x1.ffff,ffff,ffff,fp1023 >integer ; inline
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| 
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| : most-positive-finite-float ( -- x )
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|     0x1.ffff,ffff,ffff,fp1023 >integer ; inline
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| 
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| CONSTANT: log-2   0x1.62e42fefa39efp-1
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| CONSTANT: log10-2 0x1.34413509f79ffp-2
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| 
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| : representable-as-float? ( x -- ? )
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|     most-negative-finite-float
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|     most-positive-finite-float between? ; inline
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| 
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| : (bignum-log) ( n log-quot: ( x -- y ) log-2 -- log )
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|     [ dup ] dip '[
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|         dup representable-as-float?
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|         [ >float @ ] [ frexp [ @ ] [ _ * ] bi* + ] if
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|     ] call ; inline
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| 
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| PRIVATE>
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| 
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| M: bignum log [ log ] log-2 (bignum-log) ;
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| 
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| GENERIC: log1+ ( x -- y )
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| 
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| M: object log1+ 1 + log ; inline
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| 
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| M: float log1+ dup -1.0 >= [ flog1+ ] [ 1.0 + 0.0 rect> log ] if ; inline
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| 
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| : 10^ ( x -- y ) 10 swap ^ ; inline
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| 
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| GENERIC: log10 ( x -- y ) foldable
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| 
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| M: real log10 >float flog10 ; inline
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| 
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| M: complex log10 log 10 log / ; inline
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| 
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| M: bignum log10 [ log10 ] log10-2 (bignum-log) ;
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| 
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| GENERIC: cos ( x -- y ) foldable
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| 
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| M: complex cos
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|     >float-rect
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|     [ [ fcos ] [ fcosh ] bi* * ]
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|     [ [ fsin neg ] [ fsinh ] bi* * ] 2bi rect> ;
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| 
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| M: float cos fcos ; inline
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| 
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| M: real cos >float cos ; inline
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| 
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| : sec ( x -- y ) cos recip ; inline
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| 
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| GENERIC: cosh ( x -- y ) foldable
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| 
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| M: complex cosh
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|     >float-rect
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|     [ [ fcosh ] [ fcos ] bi* * ]
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|     [ [ fsinh ] [ fsin ] bi* * ] 2bi rect> ;
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| 
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| M: float cosh fcosh ; inline
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| 
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| M: real cosh >float cosh ; inline
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| 
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| : sech ( x -- y ) cosh recip ; inline
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| 
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| GENERIC: sin ( x -- y ) foldable
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| 
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| M: complex sin
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|     >float-rect
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|     [ [ fsin ] [ fcosh ] bi* * ]
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|     [ [ fcos ] [ fsinh ] bi* * ] 2bi rect> ;
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| 
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| M: float sin fsin ; inline
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| 
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| M: real sin >float sin ; inline
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| 
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| : cosec ( x -- y ) sin recip ; inline
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| 
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| GENERIC: sinh ( x -- y ) foldable
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| 
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| M: complex sinh
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|     >float-rect
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|     [ [ fsinh ] [ fcos ] bi* * ]
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|     [ [ fcosh ] [ fsin ] bi* * ] 2bi rect> ;
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| 
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| M: float sinh fsinh ; inline
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| 
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| M: real sinh >float sinh ; inline
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| 
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| : cosech ( x -- y ) sinh recip ; inline
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| 
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| GENERIC: tan ( x -- y ) foldable
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| 
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| M: complex tan [ sin ] [ cos ] bi / ;
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| 
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| M: float tan ftan ; inline
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| 
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| M: real tan >float tan ; inline
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| 
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| GENERIC: tanh ( x -- y ) foldable
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| 
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| M: complex tanh [ sinh ] [ cosh ] bi / ;
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| 
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| M: float tanh ftanh ; inline
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| 
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| M: real tanh >float tanh ; inline
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| 
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| : cot ( x -- y ) tan recip ; inline
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| 
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| : coth ( x -- y ) tanh recip ; inline
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| 
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| : acosh ( x -- y )
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|     dup sq 1 - sqrt + log ; inline
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| 
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| : asech ( x -- y ) recip acosh ; inline
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| 
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| : asinh ( x -- y )
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|     dup sq 1 + sqrt + log ; inline
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| 
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| : acosech ( x -- y ) recip asinh ; inline
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| 
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| : atanh ( x -- y )
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|     [ 1 + ] [ 1 - neg ] bi / log 2 / ; inline
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| 
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| : acoth ( x -- y ) recip atanh ; inline
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| 
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| : i* ( x -- y ) >rect neg swap rect> ;
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| 
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| : -i* ( x -- y ) >rect swap neg rect> ;
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| 
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| : asin ( x -- y )
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|     dup [-1,1]? [ >float fasin ] [ i* asinh -i* ] if ; inline
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| 
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| : acos ( x -- y )
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|     dup [-1,1]? [ >float facos ] [ asin pi 2 / swap - ] if ; inline
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| 
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| GENERIC: atan ( x -- y ) foldable
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| 
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| M: complex atan i* atanh i* ; inline
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| 
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| M: float atan fatan ; inline
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| 
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| M: real atan >float atan ; inline
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| 
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| : asec ( x -- y ) recip acos ; inline
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| 
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| : acosec ( x -- y ) recip asin ; inline
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| 
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| : acot ( x -- y ) recip atan ; inline
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| 
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| : truncate ( x -- y ) dup 1 mod - ; inline
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| 
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| GENERIC: round ( x -- y )
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| 
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| M: integer round ; inline
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| 
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| M: ratio round
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|     >fraction [ /mod abs 2 * ] keep >= [ dup 0 < -1 1 ? + ] when ;
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| 
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| M: float round dup sgn 2 /f + truncate ;
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| 
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| : floor ( x -- y )
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|     dup 1 mod
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|     [ dup 0 < [ - 1 - ] [ - ] if ] unless-zero ; foldable
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| 
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| : ceiling ( x -- y ) neg floor neg ; foldable
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| 
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| : floor-to ( x step -- y )
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|     [ [ / floor ] [ * ] bi ] unless-zero ;
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| 
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| : lerp ( a b t -- a_t ) [ over - ] dip * + ; inline
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| 
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| : roots ( x t -- seq )
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|     [ [ log ] [ recip ] bi* * e^ ]
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|     [ recip 2pi * 0 swap complex boa e^ ]
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|     [ iota [ ^ * ] 2with map ] tri ;
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| 
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| : sigmoid ( x -- y ) neg e^ 1 + recip ; inline
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| 
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| GENERIC: signum ( x -- y )
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| 
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| M: real signum sgn ;
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| 
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| M: complex signum dup abs / ;
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| 
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| MATH: copysign ( x y -- x' )
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| 
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| M: real copysign >float copysign ;
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| 
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| M: float copysign
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|     [ double>bits ] [ fp-sign ] bi*
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|     [ 63 2^ bitor ] [ 63 2^ bitnot bitand ] if
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|     bits>double ;
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