ionBlock containment'><div class = "S1"><span class = "S2"><span class="S0">We can solve this as before by incorporating the permutation. </span></span></div><div class = 'CodeBlock contiguous'><div class = 'inlineWrapper outputs'><div class = "S4 lineNode"><span class = "S5"><span class="S0">x</span><span class="S0"> = backsub( U, forwardsub(L,P*b) )</span></span></div><div class="outputParagraph" style="white-space: normal; font-style: normal; color: rgb(64, 64, 64); font-size: 14px;"><div class="inlineEl