Programming Pad for RPL Programs

[Thomas Klemm]

In an article I used this SYSRPL code with stack-diagrams:

Code:

::                     ; z
  C%>%%                ; x y
  2DUP                 ; x y x y
  DUP                  ; x y x y y
  %%*SWAP              ; x y y^2 x
  %%ABS                ; x y y^2 |x|
  DUP                  ; x y y^2 |x| |x|
  %%1+                 ; x y y^2 |x| |x|+1
  DUPDUP               ; x y y^2 |x| |x|+1 |x|+1 |x|+1
  %%*                  ; x y y^2 |x| |x|+1 (|x|+1)^2
  4PICK                ; x y y^2 |x| |x|+1 (|x|+1)^2 y^2
  %%+                  ; x y y^2 |x| |x|+1 (|x|+1)^2+y^2
  %%SQRT               ; x y y^2 |x| |x|+1 √((|x|+1)^2+y^2)
  %%+                  ; x y y^2 |x| √((|x|+1)^2+y^2)+(|x|+1)
  3PICKSWAP            ; x y y^2 |x| y^2 √((|x|+1)^2+y^2)+(|x|+1)
  %%/                  ; x y y^2 |x| Q
  OVER                 ; x y y^2 |x| Q |x|
  %%1                  ; x y y^2 |x| Q |x| 1
(…)

At least it helps me to understand the program.

Cheers
Thomas