Re: confusion about real vs not real zero

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I had this exact same question when I looked at the RacketScript issue lol.

The answer is https://docs.racket-lang.org/reference/numbers.html:

a complex number with an exact zero imaginary part is a real number.

Since 0.0 is not exact, 0.0i is not a real number.

On Fri, Nov 19, 2021 at 11:59 AM Stephen Chang <[email protected]> wrote:

> In the following, why is the first considered a real number but the
> second considered not real
>
> > (real? 0.0+0i)
> #t
> > (real? 0.0+0.0i)
> #f
>
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> .
>

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<div dir=3D"ltr"><div></div><div class=3D"markdown-here-wrapper" style=3D""=
><p style=3D"margin:0px 0px 1.2em!important">I had this exact same question=
 when I looked at the RacketScript issue lol.</p>
<p style=3D"margin:0px 0px 1.2em!important">The answer is <a href=3D"https:=
//docs.racket-lang.org/reference/numbers.html">https://docs.racket-lang.org=
/reference/numbers.html</a>:</p>
<blockquote style=3D"margin:1.2em 0px;border-left:4px solid rgb(221,221,221=
);padding:0px 1em;color:rgb(119,119,119);quotes:none">
<p style=3D"margin:0px 0px 1.2em!important">a complex number with an exact =
zero imaginary part is a real number.</p>
</blockquote>
<div title=3D"MDH:PGRpdj5JIGhhZCB0aGlzIGV4YWN0IHNhbWUgcXVlc3Rpb24gd2hlbiBJI=
Gxvb2tlZCBhdCB0aGUg
UmFja2V0U2NyaXB0IGlzc3VlIGxvbC48L2Rpdj48ZGl2Pjxicj48L2Rpdj48ZGl2PlRoZSBhbnN=
3
ZXIgaXMgaHR0cHM6Ly9kb2NzLnJhY2tldC1sYW5nLm9yZy9yZWZlcmVuY2UvbnVtYmVycy5odG1=
s
OjwvZGl2PjxkaXY+PGJyPjwvZGl2PjxkaXY+Jmd0OyBJbiB0aGUgY2FzZSBvZiBjb21wbGV4IG5=
1
bWJlcnMsIGVpdGhlciB0aGUgcmVhbCBhbmQgaW1hZ2luYXJ5IHBhcnRzCmFyZSBib3RoIGV4YWN=
0
IG9yIGluZXhhY3Qgd2l0aCB0aGUgc2FtZSBwcmVjaXNpb24sIG9yIHRoZSBudW1iZXIgaGFzCmF=
u
IGV4YWN0IHplcm8gcmVhbCBwYXJ0IGFuZCBhbiBpbmV4YWN0IGltYWdpbmFyeSBwYXJ0OyBhIGN=
v
bXBsZXgKbnVtYmVyIHdpdGggYW4gZXhhY3QgemVybyBpbWFnaW5hcnkgcGFydCBpcyBhIHJlYWw=
g
bnVtYmVyLjwvZGl2PjxkaXY+PGJyPjwvZGl2PjxkaXY+PC9kaXY+" style=3D"height:0;wid=
th:0;max-height:0;max-width:0;overflow:hidden;font-size:0em;padding:0;margi=
n:0"></div></div><div>Since 0.0 is not exact, 0.0i is not a real number.<br=
></div></div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail=
_attr">On Fri, Nov 19, 2021 at 11:59 AM Stephen Chang &lt;<a href=3D"mailto=
:[email protected]">[email protected]</a>&gt; wrote:<br></div><blockq=
uote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1p=
x solid rgb(204,204,204);padding-left:1ex">In the following, why is the fir=
st considered a real number but the<br>
second considered not real<br>
<br>
&gt; (real? 0.0+0i)<br>
#t<br>
&gt; (real? 0.0+0.0i)<br>
#f<br>
<br>
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</blockquote></div>

<p></p>

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