; begin Luhns Mod
;
;!
Function A($)
Dim $c, $t

	For $c=0 to 15-($<4)
		$A = 0 + right($, 1)
		$t = 1 & $c * ($A / 5 + $A) + $A + $t
		$ = left($,~)
		If $t + $ | 4&$A + 5
			$A = 0
Endfunction


;!
;!
; end Luhns Mod