mug
... that topologically, a mug is equivalent (see picture) to a doughnut?
... that <a href="./Homeomorphism" id="mwHQ" rel="mw:WikiLink" title="Homeomorphism">topologically</a>, a <b id="mwHg"><a href="./Mug" id="mwHw" rel="mw:WikiLink" title="Mug">mug</a></b> is equivalent <i id="mwIA">(see picture)</i> to a <a href="./Doughnut" id="mwIQ" rel="mw:WikiLink" title="Doughnut">doughnut</a>?