That seems to be your convention, but Perl allows you to &-sigilize an imported subroutine:

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use POSIX;

say &ceil(1.23);
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($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
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