Programming with HP50g

[Allen]

(08-30-2015 03:43 PM)Gerson W. Barbosa Wrote:  P.S.: Here's an 11-byte 5-step HP-42S solution:

Code:


00 { 11-Byte Prgm }
01>LBL C
02 CLΣ
03 Σ+
04 RCL 14
05 RCL- 12
06 RCL× 15
07 .END.

This is a beautiful HP42S implementation,Thank you! I enjoy when a unique perspective and serendipity provide a way to program things smaller because of math tricks- I do not need special credit for that.

You asked about checksums? There are several variations on the programs checksums possible based on how the stack is collapsed at the end with the IM, 4 / or 2 / steps ( or multiply by 0.5):

\begin{equation} \frac{\operatorname{Im}(z^2) \operatorname{Re}(z^2)}{2} = \operatorname{Im}(z^2) \frac{\operatorname{Re}(z^2)}{2}= \frac{\operatorname{Im}(z^4)}{4} = \operatorname{Im}\left(\frac{z^4}{4}\right) = A^3B-AB^3 \end{equation}

I know how the authors arrived at some of the 7-step solutions- mostly through the use of LASTARG and a different factorization of the original polynomial:
hints:
#79C6h- "asp" (from rjn)
#72B5h- "psa" (from jkh)
#E090h- "pas"
#E8BAh- "sap"