From: Gordon Thiesfeld Date: 2007-08-18T04:05:00+09:00 Subject: Re: Array Difference > Why the difference doesn't work like [1, 2] - [2] ? > -- Prova.new(2) and Prova.new(2) are two different objects. But with Fixnums, there is only ever one 2. ?> p1 = [Prova.new(1), Prova.new(2)] => [#, #] >> p2 = [Prova.new(2)] => [#] >> puts (p1 - p2) 1 2 => nil >>