Function A($)	
	$a = $^0
	dim $i, $x, $b[$a-1],$s
	
		for $i = $a-1 to 0 step -1
			$x = substr($,$i+1,1)
			if $s
				;$x = 2*$x
				;$x = $x-9*($x>9)
				$x = 2*$x+(4<$x) ; above lines combined
			endif
			$b[$i] = $x
			$s=$s^1
		next

		$i = execute("$X="+join($b,'+'))

		$a = ($>3 & $<7 & $a=16-($<4) & $x mod 10=)*left($,1)
Endfunction

Function A($)	
	$a = $^0
	dim $i, $x, $b[$a-1],$s
	
		for $i = $a-1 to 0 step -1
			$x = substr($,$i+1,1)
;			if $s
;				$x = 2*$x+(4<$x)
;			endif
			$b[$i] = $s*((4<$x)+$x)+$x ;replaces the commented out if statement
			$s=$s^1
		next

		$i = execute("$X="+join($b,'+'))

		$a = ($>3 & $<7 & $a=16-($<4) & $x mod 10=)*left($,1)
Endfunction

Function A($)	
	$a = $^0
	dim $i, $x, $b[$a-1],$s

;		for $i = $a-1 to 0 step -1 too long. fixing.
		for $i = -$a to -1
			$x = substr($,-$i,1)
			$b[~$i] = $s*((4<$x)+$x)+$x
			$s=$s^1
		next

		$i = execute("$X="+join($b,'+'))
		$a = ($>3 & $<7 & $a=16-($<4) & $x mod 10=)*left($,1)
Endfunction

Function A($)
Dim $c, $t

	For $c=0 to 15-($<4)
		$A = 0 + right($, 1)
		$t = (1&$c) * (1.1*$A) + $A + $t
		$ = left($,~)
		If $t mod 10 + $ | 4&$A + 5
			$A = 0
Endfunction

Function A($)
Dim $t,$x

For $t=0 to 15-($<4)
 $a=Right($,1)
 $x=(1&$t) *(1.1*$a)+$a+$x
 $a=(2<$a & 7>$ & $x mod 10=)*$a
 $=Left($,~)
EndFunction

Function A($)
Dim $t,$x

For $t=0 to 15-($<4)
 $a=Right($,1)
 $x=(1&$t) *(1.1*$a)+$a+$x
 $a=(2<$ & 7>$ & $x mod 10=)*$a
 $=Left($,~)
EndFunction

Function A($)
Dim $c, $t

	For $c=0 to 15-($<4)
		$A = 0 + right($, 1)
		$t = $A + 1.1*$A*(1&$c) + $t
		$ = left($,~)
		If $t mod 10 + $ | 4&$A + 5
			$A = 0
Endfunction

KiXtart Golf Score
Tournament       = KiXtart Golf: Luhn's Mod
Processing Start = 2010/08/14 12:05:58.799
Processing End   = 2010/08/14 12:05:58.808
Duration         = 0000/00/00 00:00:00.008
# Tests Run      = 40
# Tests Passed   = 26
# Tests Failed   = 14
Result           = failed
KiXGolf Score    = 126

Function A($)	
	$a = $^0
	dim $i, $x, $b,$s

		for $i = -$a to -1
			$x = substr($,-$i,1)
			$b = $b+'+'+($s*((4<$x)+$x)+$x)
			$s=$s^1
		next

		$i = execute("$X="+$b)
		$a = ($>3 & $<7 & $a=16-($<4) & $x mod 10=)*left($,1)
Endfunction

Function A($)	
	$a = $^0
	dim $i, $x, $b,$s

		for $i = -$a to -1
			$x = substr($,-$i,1)
			$b = $b+$s*((4<$x)+$x)+$x
			$s=$s^1
		next
		$a = ($>3 & $<7 & $a=16-($<4) & $b mod 10=)*left($,1)
Endfunction

Function A($)
	dim $i, $x, $b,$s

		for $i = -($^) to -1
			$x = substr($,-$i,1)
			$b = $b+$s*((4<$x)+$x)+$x
			$s=$s^1
			$a = ($>3 & $<7 & ($^)=16-($<4) & $b mod 10=)*left($,1)
Endfunction

Function A($)
	dim $i, $x, $b,$s

		for $i = -($^) to -1
			$x = substr($,-$i,1)
			$b = $b+$s*((4<$x)+$x)+$x
			$s=$s^1
			$a = ($>3 & $<7 & ($^)=16-($<4) & $b mod 10=)*$x
Endfunction