On 4 févr. 2011, at 17:06, Igor Stasenko wrote:

Since Collection includes #difference: protocol,

i just thought that the default equality could be expressed like following:

Collection>>= otherCollection ^ (self difference: otherCollection) isEmpty

In other words, if two things having no differences, then they are equal. No? :)

Need to check the species too. I believe an array is different from a set even if they contain the same elements. Noury