[FOM] Historical notation question

Brian Postow bpostow at union.edu
Tue Feb 24 10:19:23 EST 2004


I've been wondering this for a while, and since someone else just
asked me, I though I'd ask here. Does anyone know the origin of the notation
\Sigma_i and \Pi_i for the different levels of the arithmetic
hierarchy? 

Thanks

Brian Postow



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