System RPL - How to exit indefinite loop?

[Strike1]

What is the best way to drop out of this indefinite loop, BEGIN … AGAIN? I think I would need to generate an error. But how? The complete code is from Joe Horn’s Full Reset Stack. A double tap of the ON key is supposed to drop out of the program but couldn’t see anything that actually does that. I figured I would need to do that on my own. My guess is to generate an error, do a STOF, and drop out. I’m sure I’m making this way too simplistic. But I’m looking for a place to start.

::
xRCLF
InitSysUI
::
INCOMPDROP
PTR 2F3AA
BEGIN
…
…
…
BEGIN
…
…
…
DUP#0=
UNTIL
…
…
ClrDAsOK
GetKeyOb
ERRSET
DoKeyOb
ERRTRAP
SysErrorTrap
AGAIN
;
ERRTRAP
VLM
;
@