='hljl-oB'>=</span><span class='hljl-t'> </span><span class='hljl-n'>S</span><span class='hljl-oB'>-</span><span class='hljl-p'>(</span><span class='hljl-n'>ifrac</span><span class='hljl-oB'>+</span><span class='hljl-n'>ifrac_noise</span><span class='hljl-p'>)</span><span class='hljl-t'>
        </span><span class='hljl-n'>du</span><span class='hljl-p'>[</span><span class='hljl-ni'>2</span><span class='hljl-p'>]</span><span class='hljl-t'> </span><span class='hljl-oB'>=</span><span class='hljl-t'> </span><s