+---------------+
| Problem Set 7 |
+---------------+


Problem 1
=========

There were two correct solutions:
Either to construct a "layer 0" for the Probe algorithm,
converting the lossless duplicating reordering channel into a
lossy reordering nonduplicating channel and then using Probe.

The other solution is to use an exponential growth scheme,
where each message is sent more times than it ever has, and also
require response messages from P2.

+1 point for the claim that the theorem no longer holds
+3 points for constructing a "layer 0" for Probe,
        a lossy, reordering, but non-duplicating channel
+3 points for using Probe on top of layer 0
+3 for reasonable argument of correctness

Incorrect Answers:

3-5 points for trying to use the proof for 22.8 even though it doesn't work,
        depending on how well argued



Problem 2
=========

CORRECT ANSWER = 3
LEMMA 22.9 OR EQUIVALENT = 2
CORRECT PART OF PROOF ATTACKED = 2
PROOF OF WORKING CHANGE = 3


Problem 3
=========