#permission=0

SET,vn #${@caller}::${@def}
SET,vl ${@0}
DEFAULT,vl 0

IF ?{NOT ?{ISSET ${vn}}}
	SAY,{${vl}} * Var '${@def}' not defined.
	RETURN
ENDIF

SET,vv ${${vn}}
SAY,{${vl}} * Var '${@def}' = '${vv}'

UNSET vv
UNSET vn
UNSET vl