! :folding=indent:collapseFolds=0:

! $Id$
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! Copyright (C) 2003, 2004 Slava Pestov.
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IN: math
USE: combinators
USE: kernel
USE: logic
USE: stack

: integer? dup fixnum? swap bignum? or ;
: rational? dup integer? swap ratio? or ;
: real? dup number? swap complex? not and ;

: odd? 2 mod 1 = ;
: even? 2 mod 0 = ;

: f>0 ( obj -- obj )
    #! If f at the top of the stack, turn it into 0.
    f 0 replace ;

: 0>f ( obj -- obj )
    #! If 0 at the top of the stack, turn it into f.
    0 f replace ;

: max ( x y -- z )
    2dup > [ drop ] [ nip ] ifte ;

: min ( x y -- z )
    2dup < [ drop ] [ nip ] ifte ;

: between? ( x min max -- ? )
    #! Push if min <= x <= max. Handles case where min > max
    #! by swapping them.
    2dup > [ swap ] when  >r dupd max r> min = ;

: sq dup * ; inline

: pred 1 - ; inline
: succ 1 + ; inline

: neg 0 swap - ; inline
: recip 1 swap / ; inline