HP 48gII - Manual (Page 815)

Page E-4
Step C3 Step C4
Step C5 = Step B5 = Step A6
The expression tree for the expression presented above is shown next:
The steps in the evaluation of the three terms (A1 through A6, B1 through B5,
and C1 through C5) are shown next to the circle containing numbers,
variables, or operators.