if [ "$D_POS0" == "N/A" -o "$D_POS1" == "N/A" ]; then
[[ $O_POS0 -lt $O_POS1 ]] ||
error "(7.1) $O_POS1 is not larger than $O_POS0"
if [ "$D_POS0" == "N/A" -o "$D_POS1" == "N/A" ]; then
[[ $O_POS0 -lt $O_POS1 ]] ||
error "(7.1) $O_POS1 is not larger than $O_POS0"