Interesting, seems the "comments>0" op is undocumented, couldn't find it anywhere on the algolia page. Is there a page with all the different operators you can use?

It's documented here: https://hn.algolia.com/help. You have to click 'help' at the bottom of the search page, I guess.

Another option I use, which doesn't appear on that page, is storyText=none, if you want to exclude matches from text posts. That one has to go in the URL, though. Note the difference between the link in my GP comment vs. this one:

https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...

The latter creates much cleaner search results if you want to match just on title and URL.