-# If we don't delete c, we look at the gap between a and c. If this
-# gap is not too long (according to any of the minimum/extent pairs)
-# then it is OK to delete b. (A gap is too long if it's longer than a
-# relevant pair's minimum, but a pair isn't relevant if c is older
-# than the extent.) If we delete b then current c becomes the new b.
-#
-# If we don't delete either then b and c become the new a and b.
-
-- because b is clearly sufficient to
-# satisfy the
-# if we delete
-
-# {l,a,b,c}{s,n,a} = seconds, name of a,b,c where
-# c is one we're looking at now and
-# b is previous one
-# a is one before that
-# l is last (most recent)
-# where a, b, c have not been removed
-
-as=''
-an=''
-bs=''
-bn=''
-
-remove () {
- echo "expire $1 (have $2)"
-}