#!perl -slw
use threads;

sub t1 {
    eval{ use Math::GMP };
    my $mbi = Math::GMP->new($_[0]);
    return $mbi;
}

my $th1 = threads->new(\&t1, '123' x 11);

my $ret1 = $th1->join;

print Math::GMP::get_str_gmp($ret1, 10);