<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Thu, Mar 30, 2017 at 3:39 PM, Robert Bennett via swift-evolution <span dir="ltr"><<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>></span> wrote:<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>(for instance, mathematical sets may contain anything at all, including themselves)</blockquote><div><br></div><div>Well <a href="https://en.wikipedia.org/wiki/Axiom_of_regularity">actually they can’t</a>, for…<a href="https://en.wikipedia.org/wiki/Russell%27s_paradox">reasons</a> :-)</div><div><br></div><div>Nevin</div></div></div></div>