Dev comparison tests

Hi Nicholas - in the "try online" page I typed "3 3 lte" and it told me "false", so there's definitely a bug there.

One general issue is that sometimes (in the code and documentation) "top-of-the-stack" is on the left, and sometimes it's on the right, which will be a source of confusion for anyone looking at the code.

I would suggest going for a "top-of-the-stack-on-the-right" convention in all cases, which would mean reversing the order of argument specs in the 'cmd' macro.

I think I got everything the right way round in this commit.

Philip.