Natural Number game not responding

Stream: new members

[Francis Southern]

I'm playing the Natural Number game and I've got as far as Advanced Addition world and I did something silly (I typed "repeat {rw add_comm}" because I wanted to rewrite both sides of the equality "a + t = b + t"). Now I just get the message "Lean is busy ..." because I suppose it's still rewriting "a + t" to "t + a" and back. Is there anything I can do to stop or reset Lean? If I press the reset button, will it reset my progress for just this world, or the whole game?
Thanks in advance for any help.

[Kevin Buzzard]

Can you just delete the repeat {rw} line and then reload the page?

[Francis Southern]

Oh, yes, that worked! I'd already deleted the line, but I hadn't thought of reloading the page. I suppose I had assumed it would lose my progress...
Thank you very much! (And I love the game, by the way.)

[Kevin Buzzard]

I wasn't entirely sure what would happen either, I didn't do any of the web stuff.