pcwalton said a correctness proof of the type system is in-progress [1].<p>[1] <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=7601944" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=7601944</a>