Using LASTARG to Recover from Stupid Keyboard Mistakes
                             by Joe Horn

It is strange that none of the G Series manuals make any mention of
the three special uses of LASTARG for error recovery.  Same as in the
S Series, they are:

(1) PURGE in a *program* only stores the argument into LASTARG, but
    pressing the PURGE *key* (iff there's a single untagged name on
    level 1) stores BOTH the name AND ITS FORMER CONTENTS into
    LASTARG, so that you can easily recover from an accidental PURGE
    by pressing LASTARG STO.

(2) STO in a *program* stores the two arguments into LASTARG, but
    pressing the STO *key* (iff there's a single untagged name on
    level 1) stores the name AND ITS FORMER CONTENTS into LASTARG, so
    that you can easily recover from an accidental STO by pressing
    LASTARG STO LASTARG.

(3) Pressing left-shift [varname] stores BOTH varname AND ITS FORMER
    CONTENTS into LASTARG, so that you can recover from an accidental
    left-shift [varname] by pressing LASTARG STO LASTARG DROP.

Note: If the object accidentally stored in (2) or (3) is a directory
object, then LASTARG STO will error ("Directory Not Allowed"), but you
can use LASTARG RCL LASTARG DUP PGDIR ROT SWAP STO to recover.

-jkh-