Schema of a binary symmetric channel.
Benjamin D. Esham (<a href="//commons.wikimedia.org/wiki/User:Bdesham" title="User:Bdesham">bdesham</a>)
Based upon a nearly-identical version created by <a href="https://en.wikipedia.org/wiki/User:Gene.arboit" class="extiw" title="en:User:Gene.arboit">gene.arboit</a>.  This rendering done by <a href="//commons.wikimedia.org/wiki/User:Bdesham" title="User:Bdesham">bdesham</a> in Inkscape.