鐃緒申鐃祝なっわ申調鐃駿てみまわ申鐃緒申鐃緒申

www.textfile.org - 0鐃緒申0鐃緒申 鐃緒申由
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"a0 = 1" 鐃緒申鐃緒申鐃緒申笋刻申鐃緒申 1 鐃塾よう鐃祝思わ申鐃暑が鐃緒申 "0n = 0" 鐃緒申鐃緒申鐃緒申笋刻申鐃緒申 0 鐃塾よう鐃祝わ申廚鐃緒申討鐃緒申襦ｏ申鐃緒申鐃緒申鐃緒申鐃緒申呂匹鐃緒申鐃緒申鐃緒申鐃緒申鐃緒申

Javascript

Math.pow( , )

Perl

% perl -le 'print 0**0'
1

複鐃叔随申鐃祝わ申鐃銃わ申鐃緒申鐃旬￥申

#!/usr/bin/env perl -l
use strict;
use Math::Complex;
my $z0 = cplx(0,0);
print "$z0 ** $z0 == ", $z0**$z0;

%perl cpow.pl
0 ** 0 == 1

Ruby

% ruby -e 'p 0**0'
1

#!/usr/bin/env ruby
include Math
require 'complex'
z0 = Complex(0,0);
p z0**z0
puts z0**z0

% ruby cpow.rb
Complex(1, 0)
1+0i

Python

% python -c 'print 0**0'
1

C

鐃緒申密鐃祝わ申libm鐃緒申C++鐃熟常申略鐃緒申

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(int argc, char **argv){ 
    double x = argc > 1 ? atof(argv[1]) : 0.0;
    double y = argc > 2 ? atof(argv[2]) : 0.0;
    return printf("pow(%f, %f) == %f\n",x, y, pow(x,y)); 
}

% gcc -Wall -W -lm -o pow pow.c
% ./pow 
pow(0.000000, 0.000000) == 1.000000

scheme

鐃緒申鐃緒申鐃緒申gauche

% gosh
gosh> (expt 0 0)
1

Haskell

% ghci
   ___         ___ _
  / _ \ /\  /\/ __(_)
 / /_\// /_/ / /  | |      GHC Interactive, version 6.6, for Haskell 98.
/ /_\\/ __  / /___| |      http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|      Type :? for help.

Loading package base ... linking ... done.
Prelude> 0^0
1
Prelude> 0**0
1.0

bc

% bc
bc 1.06
Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'. 
0^0
1

鐃緒申鐃緒申鐃淑ってわ申鐃緒申函鐃緒申濔鐃薯サポ￥申鐃夙わ申鐃銃わ申鐃銃わ申鐃緒申0**0!=1鐃淑醐申鐃曙が存鐃淳わ申鐃淑わ申鐃緒申鐃夙ても気鐃祝なる。鐃緒申鐃緒申鐃緒申鵑修鐃緒申鐃緒申鐃緒申鐃緒申薀刻申鐃竣ワ申鐃夙ワ申鐃緒申鐃竣で種申鐃緒申鐃緒申鐃緒申里呂鐃緒申鐃緒申討鐃緒申慮鐃緒申鐃叔は器申単鐃祝でわ申鐃緒申里任呂鐃緒申鐃塾わ申鐃緒申鐃宿￥申

Dan the Nullingual Powered by Null

鐃宿居申:

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鐃純え鐃緒申 C99 (ISO/IEC 9899;1999) 鐃緒申 math.h 鐃祝含まわ申鐃� pow 鐃舜随申鐃熟￥申鐃緒申隼愎鐃緒申鐃塾常申鐃緒申鐃� 0 鐃緒申与鐃緒申鐃緒申譴随申鐃順，鐃宿メイ鐃藷エラー鐃緒申鐃瞬わ申鐃緒申鐃緒申鐃緒申鐃緒申鐃銃わ申鐃緒申 [C99] 鐃緒申

鐃緒申鐃曙、鐃瞬ドメイ鐃藷エラー鐃緒申鐃瞬わ申鐃緒申鐃盾あ鐃緒申鐃竣でわ申鐃粛￥申鐃緒申文鐃熟以駕申鐃塾とわ申鐃所。

p.229
The pow functions compute x raised to the powery. A domain error occurs if x is finite and negative and y is finite and not an integer value. A range error may occur. A domain error may occur if x is zero and y is zero. A domain error or range error may occur if x is zero andyis less than zero.

鐃叔￥申GCC鐃叔はわ申鐃緒申粉鐃緒申鐃緒申任鐃緒申鐃�

man pow (On OS X, gcc 4.01) 
     pow(x, +-0) returns 1 for any x, even a NaN.
man pow (On FreeBSD 6-Stable, gcc 3.4.4) 
     The function pow(x, 0) returns x**0 = 1 for all x including x = 0, infin-
     ity, and NaN .  Previous implementations of pow may have defined x**0 to
     be undefined in some or all of these cases.  Here are reasons for return-
     ing x**0 = 1 always:

     1.      Any program that already tests whether x is zero (or infinite or
             NaN) before computing x**0 cannot care whether 0**0 = 1 or not.
             Any program that depends upon 0**0 to be invalid is dubious any-
             way since that expression's meaning and, if invalid, its conse-
             quences vary from one computer system to another.

     2.      Some Algebra texts (e.g. Sigler's) define x**0 = 1 for all x,
             including x = 0.  This is compatible with the convention that
             accepts a[0] as the value of polynomial

                   p(x) = a[0]*x**0 + a[1]*x**1 + a[2]*x**2 +...+ a[n]*x**n

             at x = 0 rather than reject a[0]*0**0 as invalid.

     3.      Analysts will accept 0**0 = 1 despite that x**y can approach any-
             thing or nothing as x and y approach 0 independently.  The reason
             for setting 0**0 = 1 anyway is this:

                   If x(z) and y(z) are any functions analytic (expandable in
                   power series) in z around z = 0, and if there x(0) = y(0) =
                   0, then x(z)**y(z) -> 1 as z -> 0.

     4.      If 0**0 = 1, then infinity**0 = 1/0**0 = 1 too; and then NaN**0 =
             1 too because x**0 = 1 for all finite and infinite x, i.e., inde-
             pendently of x.