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I can get a modular reciprocal with Pari easily enough, eg:

```  use Math::Pari qw/ PARI Mod /;
my(\$n, \$p) = map PARI(\$_), (3, 17);
my \$recip = PARI(1) / Mod(\$n, \$p);
print "1 / \$n == \$recip\n";
1 / 3 == Mod(6,17)

The result "Mod(6,17)" is a modular value, representing the equivalence class of integers equivalent to 6 (mod 17), and that's great.

However I now want to get the "6" out of there as an integer for further work, i.e. to get the "common residue" of that modular number. I haven't found anything in the Math::Pari or Pari/GP docs that tells how to do that, and everything I've tried gives an error:

```  \$int = int(\$recip);
PARI:   ***   incorrect type in comparison. at -e line 1.

\$int = pari2num(\$recip);
PARI:   ***   forbidden assignment t_INTMOD --> t_REAL. at -e line 1.

\$int = pari2iv(\$recip);
PARI:   ***   incorrect type in gtolong. at -e line 1.

I could pull the value out with a regexp, but that would be silly. Surely there is a simple, efficient way to do this?

Hugo

In reply to Using modular numbers with Math::Pari by hv

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