4-banger?

[Dieter]

(01-23-2014 07:29 PM)Gerson W. Barbosa Wrote:  No x<=y? This appears to be very useful and important, otherwise it wouldn't be the second test available on the HP-12C, along with x=0.

Any test that includes an OR operator (like X≤Y? or X≥0?) can be replaced by a combination of two other tests. In this case, X≤Y? is the same as X≠Y? followed by X<Y?.

So if the number of tests really is limited, the device should provide <, >, = and ≠. Everything else can be assembled easily.

On the other hand, we should expect a full set of all 12 tests on a current calculator. Memory is not an issue these days. I also like the tests against 1 as provided by the 34s. Which would make a total of 18 tests.

Addendum: I just recalled the days when I did some programming on a TI-58/59. These had merely two (!) test commands: x≤t? and x=t?. Tests against zero were accomplished by clearing t beforehand (using the CP command), and the missing x>t? and x≠t? tests were handled by a preceding INV that inverted the command that followed. Well, at least this INV thing is something I could find useful on the one or other HP as well. Imagine how much key space this would save.

Dieter