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diff --git a/demo2/premise.py b/demo2/premise.py
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+++ b/demo2/premise.py
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+# Python modules
+import time
+import sys
+PY_MAJOR_VERSION = sys.version_info[0]
+# hashlib is only available in Python >= 2.5. I still want to support 
+# older Pythons so I import md5 if hashlib is not available. Fortunately
+# md5 can masquerade as hashlib for my purposes.
+try:
+    import hashlib
+except ImportError:
+    import md5 as hashlib
+
+# 3rd party modules
+import sysv_ipc
+
+# Utils for this demo
+import utils
+if PY_MAJOR_VERSION > 2:
+    import utils_for_3 as flex_utils
+else:
+    import utils_for_2 as flex_utils
+
+utils.say("Oooo 'ello, I'm Mrs. Premise!")
+
+params = utils.read_params()
+
+# Create the message queue.
+mq = sysv_ipc.MessageQueue(params["KEY"], sysv_ipc.IPC_CREX)
+
+# The first message is a random string (the current time).
+s = time.asctime()
+utils.say("Sending %s" % s)
+mq.send(s)
+what_i_sent = s
+
+for i in range(0, params["ITERATIONS"]):
+    utils.say("iteration %d" % i)
+    
+    s, _ = mq.receive()
+    s = s.decode()
+    utils.say("Received %s" % s)
+
+    # If the message is what I wrote, put it back on the queue.
+    while s == what_i_sent:
+        # Nothing new; give Mrs. Conclusion another chance to respond.
+        mq.send(s)
+        
+        s, _ = mq.receive()
+        s = s.decode()
+        utils.say("Received %s" % s)
+
+    # What I read must be the md5 of what I wrote or something's 
+    # gone wrong.
+    if PY_MAJOR_VERSION > 2:
+        what_i_sent = what_i_sent.encode()
+    try:
+        assert(s == hashlib.md5(what_i_sent).hexdigest())
+    except AssertionError:
+        flex_utils.raise_error(AssertionError, "Message corruption after %d iterations." % i)
+
+    # MD5 the reply and write back to Mrs. Conclusion.
+    s = hashlib.md5(s.encode()).hexdigest()
+    utils.say("Sending %s" % s)
+    mq.send(s)
+    what_i_sent = s
+
+utils.say("")
+utils.say("%d iterations complete" % (i + 1))
+
+utils.say("Destroying the message queue.")
+mq.remove()