sub calcolo {
    my $rRecs = shift;

    # Number of records
    my $found_recs = @{$rRecs};

    for my $rRec (@$rRecs) {
        # compute partial values
        my ($u, $superclass, $rel, $v) = @$rRec;
        ....
    }

    # combine partials
    return  $partials / $found_recs;  # or some such...
}