I only have a Camel II, which doesn't list arity in the operator table, so I'm not sure exactly what you are seeing. However, arity has nothing to do with precedence; !$seen{$_}++ works because ++ has higher precedence than !.

In reply to Re^2: What does !$saw{$_}++ means by ysth
in thread What does !$saw{$_}++ means by nwkcmk

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