Re: Question about undocumented notation.

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On Mon 6 Jul, 2026, at 21:31, Juan Jos=C3=A9 Alba Gonz=C3=A1lez wrote:

> Hi. In the OEIS I run into the following line of pari code:
>
> intnum(x=3D0, [[1], 1], 1/gamma(1+x))
>
> Apparently, this is equivalent to
>
> intnum(x=3D0, [+oo, 1], 1/gamma(1+x))
>
> but the documentation doesn't mention anything like that.
>
> I'm wondering if they are actually equivalent and why apparently [1] is
> replaced by +oo in this context.
>

   [1] was the old way to indicate infinity before the introduction of oo.
If you
  examine [1] and oo, you'll discover they are similar:
oo
\x
Result:[&=3D000055c3ad5609e0] INFINITY(lg=3D2,CLONE):
  3300000000000002 000055c3ad5609f0
  1st component =3D [&=3D000055c3ad5609f0] INT(lg=3D3):0200000000000003
  (+,lgefint=3D3):4000000000000003 0000000000000001

[1]
\x
Result: [&=3D000055c3ad560a50] VEC(lg=3D2,CLONE):
  2300000000000002 000055c3ad560a60
  1st component =3D [&=3D000055c3ad560a60] INT(lg=3D3):0200000000000003
  (+,lgefint=3D3):4000000000000003 0000000000000001

     Best,

        Lo=C3=AFc

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<div dir=3D"ltr"><div dir=3D"ltr"><div class=3D"gmail_quote"><div class=3D"=
gmail_attr">O<span class=3D"gmail_default" style=3D"font-family:verdana,san=
s-serif">n</span> <span class=3D"gmail_default" style=3D"font-family:verdan=
a,sans-serif">Mon</span>=C2=A06 <span class=3D"gmail_default" style=3D"font=
-family:verdana,sans-serif">Jul,</span>=C2=A02026<span class=3D"gmail_defau=
lt" style=3D"font-family:verdana,sans-serif">,</span>=C2=A0<span class=3D"g=
mail_default" style=3D"font-family:verdana,sans-serif">at</span> 21:31, Jua=
n Jos=C3=A9 Alba Gonz=C3=A1lez <span class=3D"gmail_default" style=3D"font-=
family:verdana,sans-serif">wrote</span>:<br></div><blockquote class=3D"gmai=
l_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,20=
4,204);padding-left:1ex"><div dir=3D"ltr"><div>Hi. In the OEIS I run into t=
he following line of pari code:</div><div><br></div><div>intnum(x=3D0, [[1]=
, 1], 1/gamma(1+x))</div><div><br></div><div>Apparently, this is equivalent=
 to</div><div><br></div><div><div>intnum(x=3D0, [+oo, 1], 1/gamma(1+x))</di=
v><div><br></div></div><div>but the documentation doesn&#39;t mention anyth=
ing like that.</div><div><br></div><div>I&#39;m wondering if they are actua=
lly equivalent and why apparently [1] is replaced by=C2=A0+oo in this conte=
xt.</div></div></blockquote><div><br></div><div style=3D"font-family:verdan=
a,sans-serif" class=3D"gmail_default">=C2=A0 =C2=A0[1] was the old way to i=
ndicate infinity before the introduction of oo. If you</div><div style=3D"f=
ont-family:verdana,sans-serif" class=3D"gmail_default">=C2=A0 examine [1] a=
nd oo, you&#39;ll discover they are similar:</div><div style=3D"font-family=
:verdana,sans-serif" class=3D"gmail_default">oo</div><div style=3D"font-fam=
ily:verdana,sans-serif" class=3D"gmail_default">\x</div><div style=3D"font-=
family:verdana,sans-serif" class=3D"gmail_default">Result:[&amp;=3D000055c3=
ad5609e0] INFINITY(lg=3D2,CLONE):</div><div style=3D"font-family:verdana,sa=
ns-serif" class=3D"gmail_default">=C2=A0 3300000000000002 000055c3ad5609f0 =
<br>=C2=A0 1st component =3D [&amp;=3D000055c3ad5609f0] INT(lg=3D3):0200000=
000000003</div><div style=3D"font-family:verdana,sans-serif" class=3D"gmail=
_default">=C2=A0 (+,lgefint=3D3):4000000000000003 0000000000000001 <br></di=
v><div style=3D"font-family:verdana,sans-serif" class=3D"gmail_default"><br=
></div><div style=3D"font-family:verdana,sans-serif" class=3D"gmail_default=
">[1]</div><div style=3D"font-family:verdana,sans-serif" class=3D"gmail_def=
ault">\x</div><div style=3D"font-family:verdana,sans-serif" class=3D"gmail_=
default"><div style=3D"font-family:verdana,sans-serif" class=3D"gmail_defau=
lt">Result: [&amp;=3D000055c3ad560a50] VEC(lg=3D2,CLONE):</div><div style=
=3D"font-family:verdana,sans-serif" class=3D"gmail_default">=C2=A0 23000000=
00000002 000055c3ad560a60 <br>=C2=A0 1st component =3D [&amp;=3D000055c3ad5=
60a60] INT(lg=3D3):0200000000000003</div><div style=3D"font-family:verdana,=
sans-serif" class=3D"gmail_default">=C2=A0 (+,lgefint=3D3):4000000000000003=
 0000000000000001</div><div style=3D"font-family:verdana,sans-serif" class=
=3D"gmail_default"><br></div><div style=3D"font-family:verdana,sans-serif" =
class=3D"gmail_default">=C2=A0 =C2=A0 =C2=A0Best,</div><div style=3D"font-f=
amily:verdana,sans-serif" class=3D"gmail_default"><br></div><div style=3D"f=
ont-family:verdana,sans-serif" class=3D"gmail_default">=C2=A0 =C2=A0 =C2=A0=
 =C2=A0 Lo=C3=AFc</div></div></div></div>
</div>

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