Thanks, a timely reminder.

I should set this as a recurring task.

Gosh, I wish I understood that.

Thanks Gregory

Nice and straightforward, I read through quickly just to check there was nothing new to me.

I write this to applaud your inclusion of the review questions at the end,...

Thanks Gregory

It's always useful to review the basics.

I think a mathematical set regards any identical member as being the same thing, so in the diagrams there would only be one...