 and <i>z</i>. Note that a wire may connect two ports of the same agent. A rewriting of a net is performed only on an active pair according to an <a href='#rules'>interaction rule</a>.</p>

<img src='../media/refs/in_net.png' width='300'/>

<h3 id='rules'>3. Rewriting Rules</h3>

<p>Here, <i>rewriting</i> is just a convenient word to express a very concrete notion of <a href='https://www.youtube.com/watch?v=_uIGQ1biCXY' target='_blank'>interaction</a>, which we shall make precise by requiring some propertie