\( \DeclareMathOperator{\abs}{abs} \newcommand{\ensuremath}[1]{\mbox{$#1$}} \)

appendix:'example'
part1: enriching-section 'operating line',revision1
[email protected],05/04/2017

(%i1) float(0.501+4.5*0.43-5.5);
\[\tag{\%{}o1}\label{o1} -3.064\]
(%i4) m:0.504;
b:0.43;
alpha :5.5;
\[\tag{m}\label{m}0.504\] \[\tag{b}\label{b}0.43\] \[\tag{alpha}\label{alpha}5.5\]
(%i7) A:(alpha-1)*m;
B:m+(alpha-1)*b-alpha;
C:b;
\[\tag{A}\label{A}2.268\] \[\tag{B}\label{B}-3.061\] \[\tag{C}\label{C}0.43\]
(%i8) p1:A+B+C;
\[\tag{p1}\label{p1}-0.3629999999999997\]
(%i9) p2:p1-A-C;
\[\tag{p2}\label{p2}-3.061\]
(%i10) p3:A+C;
\[\tag{p3}\label{p3}2.698\]

assume : b > 0 ,because -(A+C) < 0

(%i11) p4:-(A+C);
\[\tag{p4}\label{p4}-2.698\]
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