ABSTRACT
IshouldliketothankDavidPowers,FrankStewartandFritzZimmermann, aswellasEtanKohlberg,SarahStroumsaandotherparticipantsinthefourth Jahiliyyacolloquium,forcommentingonearlierdraftsofthispaper;Iam particularlyindebtedtoFrankStewart,whosereactiontothefirstdraftaccounts formostofsuchclarityasthepresentversionpossesses.
