ABORT   ?ABORT   ?ABORT?   ABORT"

ABORT

Empty the data stack and perform the function of QUIT, which includes emptying the return stack, without displaying a message.

?ABORT ( f addr u -- )

If flag is false, print message and abort.

?ABORT? ( f -- )

If flag is false, output ? and abort.

ABORT" ( f -- )

If flag, type out last word executed, followed by text xxx.