HP HP-28S - EXCO (Expand and Collect Completely)

Program
Et·m
I ENTER I
~ MULTI I STO I
Comments.
End the UNTIL clause.
End the defining program.
End the program.
Put the program on the stack.
Store
the program as MULTI.
Example. MULTI is demonstrated in the next program.
EXCO (Expand and Collect Completely)
Given an algebraic object, execute EXPAN repeatedly until the alge-
braic
doesn't change, then execute COLCT repeatedly until the
algebraic doesn't change. In some cases the result will be a number.
Arguments
Results
1 :
I algebraic I
1 :
I algebraic I
1 :
I algebraic I
1 :
z
Techniques:
• Structured programming. EXCO calls the program MULTI twice.
Even if you
don't use MULTI anywhere else, the efficiency of re-
peating all the commands in MULTI by simply including its name a
second time justifies writing MULTI as a separate program.
Required Programs:
• MULTI (page 253) repeatedly executes the programs that EXCO
provides as arguments.
28: Programming Examples 255