Thanks, roboticus, for your kind comments, and the feedback about the "long lines".  I've fixed them.

Yes you're right, it is an artifact of cut-and-paste.  I've seen it before, and usually just fix it by hand, though it can be tedious if it's a long program.  I don't know if it's the browser I'm using (Firefox), or if there's some easier way to fix it, but I'd be glad to hear of anyone else who's found a simpler solution.