if ($#TOP > $#DIR) then
	set MAX=$#DIR
else
	set MAX=$#TOP
endif
set LIMIT=$#DIR
set COUNT=1
while (${COUNT} < ${MAX} && ("${TOP[${COUNT}]}" == "${DIR[${COUNT}]}"))
	@ COUNT++
end
set REL="."
while (${LIMIT} >= ${COUNT})
	set REL=${REL}/..
	@ LIMIT--
end
switch (${COUNT})
