( a b -- )
CODE 2DROP
    HL POPqq,
    HL POPqq,
;CODE

( a b -- a b a b )
CODE 2DUP
    HL POPqq, ( b ) DE POPqq, ( a )
    chkPS,
    DE PUSHqq, HL PUSHqq,
    DE PUSHqq, HL PUSHqq,
;CODE