Help with newly installed program on TI-89

[sandy.bridge]

Is anyone familiar with the program "LM v1.0". It simplifies expressions via minterms. I have downloaded it and installed it on the TI-89, and I can find the program on the calculator. However, when I type in, exactly as the instructions say to, I get no output; that is, it merely displays what I had just typed. Kind of like typing a "2", hitting enter, then the screen displaying "2".

Here are the instructions:
This program generates exact minimal SOP or POS expression from minterm or maxterm lists, using the Quine-McCluskey algorithm.

General syntax: lm(VARS, TERMS, DON'T-CARES, MODE)
VARS: STRING of single-character variable names. e.g. "ABCD"
TERMS: LIST of Minterms (in SOP mode) or Maxterms (in POS mode). e.g {1,3,5,6}
DON'T CARES: (optional) LIST of Don't-care terms
MODE: (optional) 0 for POS mode, 1 for SOP mode (default)

NOTE: the terms must be integers. Therefore, you MUST be in either EXACT or AUTO mode.
If you forget the syntax, execute the program with no arguments: lm() to see the help screen.

Example 1:
f(a,b,c,d) = Σm(4,5,6,7,8) + d(10,11,12,13,14,15)
lm("abcd",{4,5,6,7,8},{10,11,12,13,14,15})
returns "b+ad'"

Example 2:
f(a,b,c,d) = ΠM(4,5,6,7,8) + d(10,11,12,13,14,15)
lm("abcd",{4,5,6,7,8},{10,11,12,13,14,15},0)
returns "(b')(a'+d)"

Now when I even type this exact in my calculator, it doesn't give me an output.

Here is what I type:
"lm("abcd",{4,5,6,7,8},{10,11,12,13,14,15})"

Any ideas? Do I need to "activate" the program or something? Or is there some other area I should be typing this in?

 

[Greg Bernhardt]

The author's email is simba<at>mad.scientist.com