Comments are not for extended discussion; this conversation has been <a href="http://chat.stackexchange.com/rooms/17535/discussion-on-question-by-igor-rivin-a-more-perfect-union">moved to chat</a>.
Additional examples from other users:
Not only does the link appear malformed but it is also broken. Note that the
<a href= form is used rather than the
[name](url) markdown that works in comments. I had to edit the comment to correct the problem.