->> Suppose processes A and B both have file F open, both positioned at
->> end-of-file. If A reads and B writes F at the same time, A may read
->> all, part, or none of what B writes. However, A may not read data
->> other than what B writes, e.g. if B writes nonzero data, A is not
->> allowed to see all zeros. Explain how your code avoids this race.
+>> A4: Suppose processes A and B both have file F open, both
+>> positioned at end-of-file. If A reads and B writes F at the same
+>> time, A may read all, part, or none of what B writes. However, A
+>> may not read data other than what B writes, e.g. if B writes
+>> nonzero data, A is not allowed to see all zeros. Explain how your
+>> code avoids this race.