BTW, I am CCing GemStone mailing list too because it answers false there too.��On Wed, Feb 20, 2019 at 5:26 PM Mariano Martinez Peck <marianopeck@gmail.com> wrote:Hi guys,��Look at this case:`'25' matchesRegex: '([0-9]|[1-9][0-9])' -> false``'25' matchesRegex: '([1-9][0-9]|[0-9])' -> true`That is, ( a | b ) is not euqal to ( b | a ) " a or b is not equal to b or a" and should describe a range of 0 to 99.I don't understand why the first sentence answers false. Even Pharo 1.1 answers false (so this is very very old behavior). I checked on other dialects and it answers true. I then checked here [1] and it also find matches.So...do you see some rational explanation or sounds like a bug?��----