%
O9020
#100=#5021
#101=#5023
M00
#102=#5021
#103=#5023
#104=ABS[#102-#100]
#105=ABS[
#103-#101]
#106=ATAN[#105]/[#104]
IF[#102LT#100]GOTO1
IF[#103LT#101]THEN#106=#106
IF[#103GT#101]THEN#106=-#106
G91G0Z100.
B#106
M99
N1
IF[#103LT#101]THEN#106=-#106
IF[#103GT#101]THEN#106=#106
G91G0Z100.
B#106
M99
%