Addition of positive integers 
by Kim Sullivan 
4 Jun 2002
http://alice.sunlitsurf.com/pipermail/alicebot-style/2002-June/000125.html

This is more like a 'proof of concept' than anything. I know this has been
done before by Noel (I think) but I distantly remember you had to add
further categories to support additional numbers.

The algorithm used is basically the same humans use when adding two big
numbers together- they write them below and add the digits, one by one from
right to left. AIML wildcards unfortunately match only whole words separated
by spaces, so the numerals have to be separated with spaces. A second,
slight complication, is that single words/digits can only be matched from
left, so the numbers have to be reversed before adding them.

The files 0plusx to 9plusx [N.B. All of the original files have been combined
into a single file Integer.aiml --ed.]
all contain atomic categories in the form of
CALCULATE a PLUS b that return the least significant digit of the result,
setting an additional variable (called 'remainder') to the amount of tens.

The file xplusy contains the necessary srais to add numbers with more than 1
digit.

math.aiml contains the 'wrapper' function ADD * PLUS * which provides an
error message if somehting happened. You have to adjust it a little
according to what interpreter you're using, P (and probably J) permit empty
values in the value attribute.

Note that due to a bug in D with multiple wildcards & srais this won't work
there. It doesn't run on J too, for some reason I'm not even able to
retrieve the result from the atomic categories (CALCULATE 1 PLUS 1 should
return 2 but doesn't) and it gives me a no-match when I try ADD somehing
PLUS something. As if this wasn't enough, it won't run on my own program P
version 1.4 or earlier either (get the latest 1.5). Shame on us all.

Example how it should work
ADD 1 9 5 6 PLUS 9 8 4 6
1 1 8 0 2

optimizations (more elegant naming conventions), thoughts and bug reports
are welcome, as always.

Kim

 
Bug fixes and additions

by John Campbell
http://www.jesus.org.uk

1. CALCULATE keyword changed to XCALCULATE
throughout to avoid errors with plain text
queries of the form "calculate 9 plus 9" 

2. Templates added for "CALCULATE * PLUS *" and
"ADD * AND *"

3. Carry digit restored in template for "ADD *
PLUS *"

4. Srai added before IMPLODE in same template

5. Matherr error message changed to be
explanatory and more correct. (It couldn't parse
"add 5 apples and 5 bananas" correctly)

6. template for IMPLODE * * changed to recurse
correctly, though it is ineffective on
Pandorabots and any other program that adds
spaces to "stars".