Re: Question about undocumented notation.

[Loïc Grenié <loic.grenie@gmail.com>]

On Mon 6 Jul, 2026, at 21:31, Juan José Alba González wrote:

Hi. In the OEIS I run into the following line of pari code:

intnum(x=0, [[1], 1], 1/gamma(1+x))

Apparently, this is equivalent to

intnum(x=0, [+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:[&=000055c3ad5609e0] INFINITY(lg=2,CLONE):

  3300000000000002 000055c3ad5609f0
  1st component = [&=000055c3ad5609f0] INT(lg=3):0200000000000003

  (+,lgefint=3):4000000000000003 0000000000000001

[1]

\x

Result: [&=000055c3ad560a50] VEC(lg=2,CLONE):

  2300000000000002 000055c3ad560a60
  1st component = [&=000055c3ad560a60] INT(lg=3):0200000000000003

  (+,lgefint=3):4000000000000003 0000000000000001

     Best,

        Loïc