FYI,
There is an alternate syntax using the arrow operator when calling a reference to a sub, e.g.: 
#$mul = ($x * $y * &$add_ref(10,1) * &$counter_ref());
$mul = ($x * $y * $add_ref->(10,1) * $counter_ref->());

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In reply to Re^3: Not Coder reference error - when i pass function by Refernce by Marshall
in thread Not Coder reference error - when i pass function by Refernce by pks283

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