Evolution of Conditional Tests

[Dave Britten]

(01-04-2020 12:26 AM)Valentin Albillo Wrote:  

(01-04-2020 12:08 AM)Dave Britten Wrote:  The Pioneers are pretty indecisive on this matter too:

20S, 21S: x<=y, x=0
32S: x!=y, x<y, x>y, x=y, x!=0, x<0, x>0, x=0 (No <= or >= comparisons!)
42S: All 12 comparisons present
32SII: All 12 comparisons present

The subject could be extended to also list the tests which work with alphanumerics in those models having them.

For instance, perhaps X=Y? works for either numbers or alpha strings while X<Y? may or may not work with alpha strings (which would allow sorting easily).

Thus, I suggest to expand the table to include tests which do work with alpha data in models having alpha capabilities. It would be informative and can include a surprise or two.

V.

That's a good point, though I think that only applies to the 41 and 42, correct? The 41 has real numbers and alpha strings, and the 42 adds matrices and complex numbers to that. Then you've also got the 15C with its matrix descriptors that can go on the stack, and I don't know how comparisons behave when you've switched the stack into complex mode.

The solver models (17B, 17BII, 27S, 18C, 19B, 19BII) I believe support all six comparison operators in solver equations, with comparisons between any pair of variables or constants. Not sure if the simpler equation solver in the 22S and 32SII supports any comparisons.