> I think [Simon]'d prefer if I just stopped making so many helpless newbie mistakes, but I'm really trying my best here.
No! Not at all! Your newbie mistakes are great. Really. [Well up to a point, of course. :-) ] That's why I was complaining about you erasing them! There will be many, many people on this forum who are lurking. There's not just the five people who are contributing, and there's also the people taking part who haven't caught up to here yet. When I'm correcting your mistakes I'm writing for them as well.
You are doing a sterling job of writing stuff up, and along the way do the kind of thing that most people do when they're learning. I'm pointing them out to both you and everyone else who is reading, so, as you say, you can learn, and so can the people who are just reading. What you are writing is not perfect. [What John and I write is not perfect either, but we've had many years of working at mathematical writing.] It would be very intimidating to everyone else on the course if they got the impression that the people contributing (and hence everyone else on the course except them) could write perfectly expressed mathematics.
So with this in mind, as John said, it makes more sense to others reading that you correct your posts in a subsequent comment. (You can always edit your old post to say 'see below for a revised version'.)
I'm sorry if my comments were too abrupt yesterday, that isn't the spirit in which they were intended. John was claiming the other day that I was far more polite than him, so I was trying to turn down my Britishness! The intended spirit was to help you get better at expressing yourself mathematically and to help you not fall into standard traps which lead to dodgy proofs. My students will get their written work taken apart far more than I'm doing with yours here, and, whilst it would be good if they didn't make newbie mistakes, they wouldn't have anything to learn and I'd be out of a job :-)