A Programmer's Challenge

What Is the Minimal BASIC Command Set?

When I was in college, a fellow student programmer proffered the opinion that a certain couple of keywords were critical components of any programming language.  Prompted by a small wager, I created a designated algorithm without using his "indispensable" syntax.  Subsequently, I have wondered just what are the minimal features with which one might construct a BASIC algorithm.

As with every other application, each upgrade of your favorite compiler offers new and wonderful keywords and constructs for your enjoyment.  Are they handy?  You betcha.  Are they really necessary?  Mostly not.  The essential tools for algorithm design have existed since the early days of programming; much of the rest is window dressing.

— My Proposal —

Any BASIC algorithm can be written utilizing just two of the following keywords and functions:

Math: LOG LOG2 LOG10 EXP EXP2 EXP10 SQR n^e MOD ABS SGN SWAP BIT BITS Bitwise-AND Bitwise-OR Trigonometry functions Logic: IF THEN ELSE ELSEIF ISTRUE ISFALSE IIF NOT AND OR IMP EQV XOR CHOOSE SWITCH EXTRACT MIN MAX Program flow: FOR NEXT WHILE WEND DO LOOP GOTO GOSUB ON SELECT CASE

That's right — I contend that all but two of those 50+ programming aids are expendable, and that's only a partial listing.  Furthermore, no external assistance need be employed, such as using assembler commands or shelling to a magic module that performs calculations.  The resultant code might be rather lengthy, but it can be self-sufficient.

— The Challenge —

• Which are my two secret weapons?
• How might one utilize them to get the job done?
• What minimal command set would you require?

Mind you, I am not a world-class programmer; so Kudos and my undying admiration go to anyone who can solve this puzzle.  Alternatively, if you think I'm full of shit, perhaps a little wager can be arranged!

Actually, I believe that there are two solutions to the challenge.  In any case, a real human would be happy just to talk about this stuff.